concurring in part and dissenting in part:
The Arizona Supreme Court unconstitutionally excluded mitigating evidence from its consideration because the evidence was not causally related to the crimes. As a result, Poyson was deprived of his right to an individualized capital sentencing determination under the Eighth and Fourteenth Amendments. Penry v. Lynaugh (Penry I), 492 U.S. 302, 317, 109 S.Ct. 2934, 106 L.Ed.2d 256 (1989), abrogated on other grounds by Atkins v. Virginia, 536 U.S. 304, 122 S.Ct. 2242, 153 L.Ed.2d 335 (2002); Eddings v. Oklahoma, 455 U.S. 104, 110-12, 102 S.Ct. 869, 71 L.Ed.2d 1 (1982); Lockett v. Ohio, 438 U.S. 586, 604-05, 98 S.Ct. 2954, 57 L.Ed.2d 973 (1978). Because the majority’s contrary conclusion cannot be reconciled with controlling Supreme Court precedent, I respectfully dissent.
I
“[I]n capital cases the fundamental respect for humanity underlying the Eighth Amendment ... requires consideration of the character and record of the individual offender and the circumstances of the particular offense as a constitutionally indispensable part of the process of inflicting the penalty of death.” Lockett, 438 U.S. at 604, 98 S.Ct. 2954 (alteration in original) (quoting Woodson v. North Carolina, 428 U.S. 280, 304, 96 S.Ct. 2978, 49 L.Ed.2d 944 (1976)). Accordingly, the Supreme Court has held since 1978 that a defendant facing a capital sentence must have the opportunity to present all relevant evidence in mitigation. See id. at 604-05, 98 S.Ct. 2954. Merely admitting the evidence at the penalty phase does not satisfy the constitutional mandate. Rather, to ensure that a sentence of death reflects “a reasoned moral response to a defendant’s background, character, and crime,” Penry I, 492 U.S. at 328, 109 S.Ct. 2934 (emphasis in original) (quoting Franklin v. Lynaugh, 487 U.S. 164, 184, 108 S.Ct. 2320, 101 L.Ed.2d 155 (1988) (O’Connor, J., concurring in the judgment)), the procedure for evaluating mitigating evidence must ensure that the sentencer is “able to consider and give effect to that evidence in imposing sentence,” id. at 319, 109 S.Ct. 2934 (emphasis added) (citing Hitchcock v. Dugger, 481 U.S. 393, 107 S.Ct. 1821, 95 L.Ed.2d 347 (1987)); see also Eddings, 455 U.S. at 113-14,102 S.Ct. 869. A sentencer “give[s] effect to” mitigating evidence by weighing all such admissible evidence against any aggravating circumstances proven by the state. See, e.g., Eddings, 455 U.S. at 114-15, 102 S.Ct. 869; Towery v. Ryan, 673 F.3d 933, 944-45 (9th Cir.2012). Only by viewing all sentencing evidence in context can a court render the individualized determination of moral culpability that the Constitution requires. See Lambright v. Schriro, 490 F.3d 1103, 1115 (9th Cir.2007) (per curiam).
A.court violates the constitutional command by categorically screening out certain mitigating evidence as a matter of law, before it may be weighed in combination with all other relevant sentencing evidence. Tennard v. Dretke, 542 U.S. 274, 284-86, 124 S.Ct. 2562, 159 L.Ed.2d 384 (2004); Eddings, 455 U.S. at 113-14, 102 S.Ct. 869 (holding that the sentencer may not “refuse to consider, as a matter of law, any relevant mitigating evidence”) (emphasis in original). Relevance is the only prerequisite to full consideration of mitigating evidence. See Tennard, 542 U.S. at 284-85, 124 S.Ct. 2562. While the state court may assign a relative weight to each item of admissible mitigating evidence, Towery, *1205673 F.3d at 944, it cannot impose any additional criteria, such as a causal nexus requirement, to screen such evidence from the sentencer’s ultimate view of the defendant. A sentencing procedure that automatically assigns a “weight” of zero to any mitigating evidence lacking a causal nexus to the crime is indistinguishable from an analytical “screen” that excludes such evidence from consideration as a matter of law. Thus, regardless of what label it bears, such a “weighing” procedure plainly violates Eddings. Simply altering the label attached to an unconstitutional process does not magically render it constitutional.
At the time it decided this case, the Arizona Supreme Court applied a causal nexus test similar to the one the U.S. Supreme Court held unconstitutional in Tennard. See, e.g., State v. Sansing, 206 Ariz. 232, 77 P.3d 30, 37 (2003) (“Mere evidence of drug ingestion or intoxication, however, is insufficient to establish statutory mitigation. The defendant must also prove a causal nexus between his drug use and the offense”) (footnote omitted); State v. Canez, 202 Ariz. 133, 42 P.3d 564, 594 (2002) (en banc) (citation omitted) (“[A] causal nexus between the intoxication and the offense is required to establish non-statutory impairment mitigation”); State v. Kayer, 194 Ariz. 423, 984 P.2d 31, 45 (1999) (en banc) (“A defendant must show a causal link between the alcohol abuse,' substance abuse, or mental illness and the crime itself’ for such evidence to be considered a mitigating factor)'; State v. Clabourne, 194 Ariz. 379, 983 P.2d 748, 756 (1999) (en banc) (defendant’s difficult childhood not a mitigating factor because “he has failed to link his family background to his murderous conduct or to otherwise show how it affected his behavior”); State v. Djerf, 191 Ariz. 583, 959 P.2d 1274, 1289 (1998) (en banc) (defendant’s experience of childhood abuse cannot be considered as a mitigating factor unless there is a causal connection between the abuse and the crime); State v. Jones, 188 Ariz. 388, 937 P.2d 310, 322 (1997) (defendant did not establish impaired capacity as either a statutory or non-statutory mitigating factor because “no testimony establishes, either because of his use of drugs or because he was coming' down off of the drugs, that defendant could not appreciate the wrongfulness of his conduct or conform his conduct to the law”); State v. Wallace, 160 Ariz. 424, 773 P.2d 983, 986 (1989). (en banc) (“A difficult family background, in and of itself, is not a mitigating circumstance.”).
Arizona’s causal nexus test not only violated Eddings, but a long line of Supreme Court cases holding that all relevant mitigating evidence must be considered in capital sentencing. These cases establish that evidence of a defendant’s background and character, including childhood trauma or mental health problems, is relevant in mitigation even if it does nothing to explain why the defendant committed the crime of conviction. See Penry I, 492 U.S. at 322-23, 109 S.Ct. 2934; Lockett, 438 U.S. at 604, 98 S.Ct. 2954. See also Lambright, 490 F.3d at 1115. Such evidence may reasonably diminish the defendant’s moral culpability, see Penry I, 492 U.S. at 322-23, 109 S.Ct. 2934, and “might cause a sentencer to determine that a life sentence, rather than death at the hands of the state, is the appropriate punishment for the particular, defendant,” Lambright, 490 F.3d at 1115. Placing such evidence beyond the sentencer’s effective reach is “simply unacceptable in any capital proceeding,” id. (citing Lockett, 438 U.S. at 605, 98 S.Ct. 2954), because it deprives the sentencer of the complete, multifaceted rendering of the defendant that must be the basis for capital sentencing.
Arizona’s unconstitutional causal nexus test remained in force until Tennard, and it was in use when the Arizona Supreme Court considered Poyson’s appeal.
*1206II
In reviewing pre-Tennard Arizona capital cases, we do not presume that the Arizona Supreme Court unconstitutionally refused to consider relevant mitigating evidence in' its re-weighing of aggravating and mitigating factors.1' Rather, we examine the record to determine whether the Arizona Supreme Court applied an unconstitutional cáusal nexus test to screen mitigating evidence from consideration in a particular case. In Schad v. Ryan, we affirmed the denial of habeas relief when the record contained “no indication that the state courts applied a nexus test, either as a method of assessing the weight of the mitigating evidence, or as an. unconstitutional screening mechanism.... ” 671 F.3d 708, 724 (9th Cir.2011) (per curiam). In doing so, Schad was consistent with the Supreme Court’s instruction that “[f]ederal courts are not free to presume that a state court did not comply with constitutional dictates on the basis of nothing more than a lack of citation.” Bell v. Cone, 543 U.S. 447, 455, 125 S.Ct. 847, 160 L.Ed.2d 881 (2005) (per curiam) (citations omitted).
Similarly, in Towery, we rejected the defendant’s claim that the Arizona Supreme Court unconstitutionally screened mitigating evidence that lacked a causal nexus to the crime. 673 F.3d at 944. We stressed that the state supreme court had articulated the proper standard for considering mitigating evidence. See id. In independently reviewing Tower/s mitigating evidence, the state court recognized that, “[hjaving considered family background during the penalty phase, the sentencer must give the evidence such weight that the sentence reflects a ‘reasoned moral response’ to the evidence.” Id. (alteration in original) (quoting State v. Towery (Towery I), 186 Ariz. 168, 920 P.2d 290, 311 (1996)). In light of the whole record, this statement demonstrated the Arizona Supreme Court’s awareness that it must weigh all relevant mitigating evidence against the aggravating circumstances, even if it ultimately assigned relatively little weight to that mitigating evidence which lacked a strong causal link to the crime. See id. at 944-45.
In contrast, in Styers v. Schriro, 547 F.3d 1026 (9th Cir.2008), we looked beyond the Arizona Supreme Court’s characterization of its own reasoning where the form of its analysis evidenced unconstitutional screening. See id. at 1035 (“In conducting its independent review of the propriety of Styers’- death sentence, the Arizona Supreme Court stated that it had ‘considered all of the proffered mitigation’... However, its analysis prior to this statement indicates otherwise.”) (internal citation omitted). Though the state court claimed that it “considered” all mitigating evidence, its analysis showed that it impermissibly screened Styers’ mitigating mental health evidence solely because it lacked a causal nexus to the crime. Declining to elevate form over substance, we granted the writ upon concluding that “the Arizona Supreme court appears to have imposed a test directly contrary to the constitutional requirement that all relevant mitigating evidence be considered by the sentencing body.” Id. (emphasis added) (citing Smith v. Texas, 543 U.S. 37, 45, 125 S.Ct. 400, 160 L.Ed.2d 303 (2004)).
Recently, in Lopez v. Ryan, 630 F.3d 1198 (9th Cir.2011), we declined to pre*1207sume from Arizona case law alone that “a tacit causation rule underpinned the state court’s decision” in the case at hand. Id. at 1203. Rather than “infer[ring] unconstitutional reasoning from judicial silence,” Lopez instructs that we should “look to what the record actually says.” Id. at 1204 (citing Schad, 606 F.3d at 1046-47).
The import of all these cases is that we should not presume any constitutional error from a silent record, nor should we accept without further examination a state court’s characterizations of its own reasoning. Rather, we should -look to the substance of the record itself to determine whether the state court unconstitutionally excluded relevant mitigating evidence from consideration at sentencing.
Though it insists otherwise, the majority treats the statement in Schad that relief should be denied “[ajbsent a clear indication in the record, that the state court applied the wrong standard” to create a new, more stringent test for determining whether a state court applied an unconstitutional causal nexus analysis. 671 F.3d at 724. The majority then applies this “test” to resolve purported ambiguities in the record in the state’s favor.
However, in stating that we should identify “a clear indication in the record” that the state court violated Tennard before granting habeas relief, the Schad panel was merely explaining Bell’s rule against presuming error from a silent record. No Supreme Court case imposes a “clear indication” test, nor does any case impose a rule that we must resolve ambiguities against the petitioner. To the contrary, as Justice O’Connor wrote in her Eddings concurrence, the qualitatively different nature of a death sentence requires reviewing courts “to remove any legitimate basis for finding ambiguity concerning the factors actually considered by the trial court.” 455 U.S. at 119, 102 S.Ct. 869 (O’Connor, J., concurring). In short, if there is any legitimate reason to believe that a court has excluded mitigating evidence from consideration, we should grant habeas relief so that a proper weighing of aggravating and mitigating factors can occur. The appropriate approach, taken in our more recent cases, is simply to evaluate “what the record actually says.” Lopez, 630 F.3d at 1204 (citing Schad, 606 F.3d at 1046-47).2
Moreover, because the Schad panel found “no indication that the state courts applied a nexus test, either as a method of assessing the weight of the mitigating evidence, or as an unconstitutional screening mechanism ...,” 671 F.3d at 724 (emphasis added), the case simply does not address what a “clear indication” of unconstitutional causal nexus screening looks like, nor the relationship between the purported *1208“clear indication” requirement and the statutory standards governing habeas review. Thus, even assuming that a “clear indication” of unconstitutional causal nexus screening is in fact an independent prerequisite to granting habeas relief, Schad entirely fails to support the majority’s proposition that a “clear indication” can exist only in the absence of any ambiguity in the state court’s analysis. The notion that a habeas petitioner can secure relief only by conclusively establishing the absence of any ambiguity in the state court record is patently inconsistent with the preponderance standard that defines the petitioner’s burden.3 Assuming that we and the district court faithfully apply the statutory standard for granting a certificate .of ap-pealability, we should only have the opportunity to review claims as to which the record is somewhat ambiguous. See Shackleford v. Hubbard, 234 F.3d 1072, 1081 (9th Cir.2000) (quoting Slack v. McDaniel, 529 U.S. 473, 484, 120 S.Ct. 1595, 146 L.Ed.2d 542 (2000)) (to obtain a certificate of appealability, a habeas petitioner must demonstrate “ ‘that reasonable jurists could debate whether ... the petition should have been resolved in a different manner.... ’ ”). To secure relief, the petitioner need not show that there is no conceivable ambiguity in the record that could support the state’s position; rather, he must persuade us that his evidence that the state court’s decision was contrary to clearly established federal law is stronger than the state’s.
Ill
I disagree with the majority’s conclusion that the state court’s decision is simply too ambiguous to permit meaningful habeas review. Rather, when we examine “what the record actually says,” Lopez, 630 F.3d at 1204 (citation omitted), the Arizona Supreme Court’s use of an unconstitutional causal nexus test to screen Poyson’s mitigating evidence of mental health problems and childhood abuse is readily apparent.4
The Arizona Supreme Court’s analysis in this case is substantially indistinguish*1209able from its decision in Styers, in which we found sufficient evidence of a constitutional violation to grant habeas relief. In Styers, the Arizona Supreme Court listed each item of proffered mitigation evidence: First, it noted that “Defendant had no prior convictions for either misdemeanors or felony offense[s]” and stated that “[t]his is relevant mitigating evidence.” State v. Styers, 865 P.2d at 777 (citation omitted). Next, it stated that “Defendant’s service in Vietnam and-honorable discharge are also relevant mitigating circumstances.” Id. (citation omitted). Then, the court noted that “Defendant also suffered from post-traumatic stress disorder prior to and around the time of the murder as a result of his combat service in Vietnam.” Id. The court said that “[t]his could also, in an appropriate circumstance, constitute mitigation. However, two doctors who examined defendant could not connect défen-dant’s condition to his behavior at the time of the conspiracy and murder.” Id. (internal citation omitted). The state court did not recite a comprehensive list of the mitigating factors it considered in its independent review of Styers’ death sentence; thus, it did not clarify whether Styers’ post-traumatic stress disorder would in fact “constitute mitigation.” Instead, the court asserted that “[w]e have considered all of the proffered mitigation and, like the trial court, find it is not sufficiently substantial to warrant leniency.” Id. at 777.
On habeas review, we relied on this analysis to find that the state court violated Styers’ right to an individualized capital sentencing under Eddings and Smith, notwithstanding its claim to have considered all of Styers’ proffered mitigating evidence. Styers, 547 F.3d at 1035. Though the state court acknowledged that evidence of post-traumatic stress disorder is, as a general matter, relevant in' mitigation, we found that its “use of the conjunctive adverb ‘however,’ following its acknowledgment that such evidence ‘could’ in certain cases constitute mitigation, indicates that this was not such a case.” Id. In the context of its entire analysis, this turn of phrase revealed that the state court had applied a causal nexus test “directly contrary to the constitutional requirement that all relevant mitigating evidence be considered by the sentencing body.” Id. We reaffirmed this interpretation in Schad, describing Styers as a case in which the state court “expressly disregarded” mitigating psychiatric evidence due to the defendant’s “failure to demonstrate a causal connection between the disorder and the crime.” Schad, 671 F.3d 708, 724 (9th Cir.2009) (emphasis added).
Upon close examination, the state court’s analysis in Poyson’s case is strikingly similar to that in Styers. With respect to Poyson’s mental health evidence, the Arizona Supreme Court acknowledged that Poyson “suffers from ‘certain personality disorders’ ” and did not question that evidence of such disorders is relevant in mitigation. State v. Poyson, 7 P.3d at 90. It then stated, echoing its reasoning in Styers: “[h]owever, we find no indication in the record that ‘the disorder controlled [his] conduct or impaired his mental capacity to such a degree that leniency is required.’” Id. at 90-91 (quoting State v. Brewer, 170 Ariz. 486, 826 P.2d 783, 802 (1992)). It therefore accorded Poyson’s evidence of mental health problems “no mitigating weight.” Id. at 91. Similarly, the state court acknowledged that Poyson was physically, mentally, and sexually abused a,s a child. Id. It then stated: “however, defendant did not show that his traumatic childhood somehow rendered him unable to control his conduct. Thus, the evidence is without mitigating value.” Id.5
*1210If anything, the state court provided more evidence of unconstitutional causal nexus screening in Poyson’s case than it did in Styers’. For at the end of its opinion, the state court listed all of the mitigating circumstances it considered in its independent review of Poyson’s death sentence. Id. It omitted from this critical tally both Poyson’s personality disorders and his abusive childhood. See id. (listing only “cooperation with law enforcement, age, potential for rehabilitation, and family support” as mitigating evidence in the case); see also Maj. Op. at 1194-95 (acknowledging that the state court found— and weighed — only one statutory mitigating factor (age) and three nonstatutory mitigating factors (cooperation with law enforcement, potential for rehabilitation, and family support)).
Bell forbids our ‘presuming constitutional error based on a silent record. However, like the panel that granted the writ in Styers, we are not bound to accept a state court’s characterization of its own analysis when its reasoning reveals a deprivation of constitutional rights in violation of clearly established law. This is particularly true when the result of the state court’s error is to deprivé a human being of his life.
The Eighth and Fourteenth Amendments prohibit state courts from screening mitigating evidence from full consideration based on a lack of causal nexus to the crime of conviction. In reviewing Poyson’s sentence, however, the Arizona Supreme Court applied a formula that automatically assigned a “weight” or “value” of zero to all mitigating evidence that lacked a causal nexus to the crime. Most significantly, this total devaluation of Poyson’s mitigating evidence occurred logically prior to the state court’s balancing of aggravating and mitigating circumstances. See State v. Poyson, 7 P.3d at 90-91. As such, the Arizona Supreme Court failed to “consider all relevant mitigating evidence and weigh it against the evidence of the aggravating circumstances,” Eddings, 455 U.S. at 117, 102 S.Ct. 869 (emphasis added), which prevented Poyson from presenting the totality of his individualized circumstances to the court exercising authority to condemn him to death. The “consideration” of Poyson’s mitigating evidence was without meaning where the court discarded that evidence before the critical stage of its analysis— the final balancing of mitigating and aggravating circumstances that determined his sentence. To label the process “weighing” does not make it so; screening by any other name is still screening.
The Arizona Supreme Court did not consider mitigating evidence offered by Poy-son because it lacked a causal nexus to the *1211crime. In doing so, it committed Eddings error. Remand is required.
I respectfully dissent, in part.
. Woodford v. Visciotti, 537 U.S. 19, 123 S.Ct. 357, 154 L.Ed.2d 279 (2002) (per curiam), is not to the contrary. There, the Supreme Court simply rejected our reading of the state court’s opinion; it did not instruct us to deny habeas relief whenever the state court fails to provide a "clear indication” of constitutional error. See id. at 24, 123 S.Ct. 357. While acknowledging that certain language in the state court’s opinion could be read as misstating the Strickland standard, the Woodford Court faulted us for rejecting other, stronger evidence in the opinion indicating that the state court applied the correct standard. See id. If anything, Woodford supports a close reading of state court decisions on habeas review to determine whether they contravene or unreasonably apply federal law. See id. at 23-24, 123 S.Ct. 357. As Woodford itself ..demonstrates, this approach does not offend "the presumption that state courts know and follow the law.” Id. at 24, 123 S.Ct. 357 (citations omitted). Moreover, to the extent the majority finds the Arizona Supreme Court’s opinion in this case ambiguous on the causal nexus issue, Woodford is of little help, as it simply does not address the analysis of an ambiguous state court decision on habeas review. See id. at 23, 123 S.Ct. 357 (asserting that the state court opinion at issue "painstakingly describes the [correct] Strickland standard”).
. The majority insists that, under its reasoning, Poyson need not prove the absence of any meaningful ambiguity in the state court record to secure relief. Rather, the majority asserts that Poyson's claim must fail because the record in this case "is insolubly ambiguous." Maj. Op. at 1199. Thus, we now have new categories of ambiguity: ambiguous, meaningfully ambiguous, and insoluably ambiguous. Not only are these labels distinctions without difference, these new tests are not to be found in any Supreme Court jurisprudence, which governs our considerations of AEDPA cases, nor our own. The majority does not cite a single case in which we have rejected a prisoner’s habeas claim because we simply could not figure out what the state court had said. Instead, it relies on decisions denying relief because the record — ambiguous as it might have been — ultimately showed that the state court employed a causal nexus test as a permissible weighing mechanism or did not rely on causal nexus analysis at all. Maj. Op. at 1197-98 (citing Towery, 673 F.3d at 945; Schad, 671 F.3d at 724; Lopez, 630 F.3d at 1203-04). To the extent the majority suggests that the state court decision at issue in this case is unprecedented in the extent of its ambiguity, that proposition is belied by the state court decision in Styers, which, as explained below, employed strikingly similar language yet was sufficiently comprehensible to support habeas relief. Of course, Poyson bears the burden of proof, but there is no authority for the proposition that we may throw up our hands and declare the record too ambiguous to definitively interpret one way or the other. The majority fails to recognize that the preponderance standard, by definition, permits the party bearing the burden to proof to prevail without establishing his position beyond reasonable doubt. The effect of the majority rule is to alter the burden of proof, and it flatly contracts our analysis in Styers.
. I agree with the majority that the Arizona Supreme Court did not violate Eddings in rejecting Poyson’s evidence of substance abuse as a mitigating factor, as it found that he failed to establish a significant history of substance abuse as a matter of fact.
. Though we review the Arizona Supreme Court’s opinion in this case, the sentencing court’s analysis is relevant to the extent that *1210the state supreme court generally adopted its , reasoning. Without a doubt, the sentencing court's discussion of Poyson’s proffered mitigating evidence lends greater force to his Pen-ry claim. For example, the sentencing court accepted that Poyson suffers from personality disorders, yet the sentencing judge concluded that this evidence did not "rise to the level of being a mitigating factor because I am unable to draw any connection whatsoever with such personality disorders and the commission of these offenses." (emphasis added). To the extent that the court excluded the evidence on the ground that Poyson’s mental health problems were not sufficiently severe, it erred. Evidence of mental health problems is relevant in mitigation, and a defendant need not show that such problems rise to a specified level of severity to establish their relevance. See Tennard, 542 U.S. at 284-85, 124 S.Ct. 2562. The sentencing court improperly rejected Poyson’s personality disorders as mitigating evidence because of the lack of causal connection between those disorders and the murders at issue.