OPINION ON REHEARING
BAKES,Chief Justice.
This Court granted plaintiff appellant Hilden’s petition for rehearing which raised only one issue, i.e., the correctness of the conclusion in our original opinion that the trial court did not err by giving Instruction No. 4 on proximate cause. As our original opinion pointed out, that instruction was based on IDJI 230, and defined proximate cause as “an act or omission by a defendant” which caused the plaintiff’s damages, and which damages “would not have occurred but for that act or omission, and that such act or omission was a substantial factor in causing the damages.” (Emphasis added.) In its brief in support of its petition for rehearing, appellant acknowledges that the “but for” language in Instruction No. 4 is taken from IDJI 230 and is a correct definition of proximate cause in the usual case. However, appellant argues that there is an exception to the general rule of “but for” proximate causation which applies in cases in which there are multiple “forces” or causes, all of which are a substantial factor in bringing about the death of the plaintiff, but some of which are not attributable to the defendant. Appellant argues that in such multiple cause cases the “but for” language of Instruction No. 4 (and IDJI Instruction 230) is an incorrect instruction. Appellant relies primarily upon the Restatement (Second) of Torts, § 432(2), and the case of Wilson v. City of Kotzebue, 627 P.2d 623 (Alaska 1981).
The Restatement (Second) of Torts, § 432(2) states:
(2) If two forces are actively operating, one because of the actor’s negligence, the other not because of any misconduct on his part, and each of itself is sufficient to bring about harm to another, the actor’s negligence may be found to be a substantial factor in bringing it about.
*334Hilden then cites and quotes the Alaska case of Wilson v. City of Kotzebue, which stated:
As we stated in [State v.] Abbott, [498 P.2d 712 (Alaska 1972),] the “but for” test is inapplicable when there are two (or more) forces, and each one by itself is sufficient to cause the injury. Id. at 727. In such cases, the “but for” test does not work because it would result in each force being absolved of liability. See Restatement (Second) of Torts § 432, Illustrations 3 and 4 at 431-32 (1965).
627 P.2d at 630. The Alaska court in Wilson v. Kotzebue relied on their earlier case of State v. Abbott, 498 P.2d 712 (Alaska 1972), which explained:
Normally, in order to satisfy the substantial factor test it must be shown both that the accident would not have happened “but for” the defendant’s negligence and that the negligent act was so important in bringing about the injury that reasonable men would regard it as a cause and attach responsibility to it. There is, however, one significant exception to this concurrence requirement: if two forces are operating to cause the injury, one because of defendant’s negligence and the' other not, and each force by itself is sufficient to cause the injury, then the defendant’s negligence may be found to be a substantial factor in bringing about the harm.
498 P.2d at 727 (emphasis in original). Based upon the foregoing authorities, appellant argues on rehearing that because this case involves multiple “forces” or causes of death, not all of which were attributable to the defendant Dr. Ball, the trial court erred in including the “but for” language of IDJI 230 in the proximate-cause Instruction No. 4.
In denying Hilden’s motion for new trial on this same issue, the trial court relied on the recent Idaho Court of Appeals case, Challis Irrigation Company v. State, 107 Idaho 338, 689 P.2d 230 (Ct.App.1984), which analyzed the prior decisions of this Court regarding the law of proximate cause, explaining:
The concept of proximate cause contains two components — cause in fact, and scope of legal responsibility.1 W. PROSSER, HANDBOOK OF THE LAW OF TORTS §§ 41-42 (4th ed. 1971). Here, our focus is upon cause in fact.
Proximate cause, in the sense of cause in fact, has been defined as a cause “which in natural and continuous sequence, unbroken by any efficient intervening cause, produces the result which would not have occurred.” Smith v. Sharp, 82 Idaho 420, 426, 354 P.2d 172, 175 (1960). See also Chatterton v. Pocatello Post, 70 Idaho 480, 223 P.2d 389 (1950); Pilmer v. Boise Traction Co., 14 Idaho 327, 94 P. 432 (1908). This component of proximate cause embraces two closely related elements. First, an event is the cause in fact of a succeeding event only if the succeeding event would not have occurred “but for” the prior event. Thus, an act or omission is not the cause in fact of ensuing damage if the damage likely would have occurred anyway. The second element is a requirement that the first event be a “substantial factor” in producing the succeeding event. Munson v. State Department of Highways, 96 Idaho 529, 531 P.2d 1174 (1975). *335Thus, a defendant’s conduct is the cause in fact of an event only if it was a material element and a substantial factor in bringing it about. W. PROSSER, supra, at 240; RESTATEMENT (SECOND) OF TORTS § 431 (1965).
107 Idaho at 343, 689 P.2d at 692.
At the jury instruction conference the trial court evaluated the plaintiff’s case, and the nature of the plaintiff’s claims, in order to properly choose the instructions to be given to the jury. At that time the trial court proposed a proximate cause instruction composed in the first paragraph of Plaintiff’s Requested Instruction No. 4, and in the second half the causation language from IDJI 230, which is the standard proximate cause instruction. That language includes the “but for” phrase of which appellant now complains; however, appellant did not voice any objection to that language at the instruction conference.
Appellant now contends that the trial court should have recognized that plaintiff's claim against Dr. Ball alleged that there were multiple “forces” or causes which caused Mr. Hilden’s death, not just a single cause, and therefore the court should have followed the decision of the Alaska Supreme Court in Wilson v. City of Kotzebue, supra, and not given the “but for” instruction. However, even assuming that the “but for” causation language of IDJI 230 is inappropriate in a multiple “force” or cause case, after reviewing the record of the trial proceedings up to the date of the instruction conference, and giving deference to the trial judge who presided over all the proceedings,2 we cannot conclude that the trial court erred in viewing this as a single “force” or cause case, and therefore there is no basis for the appellant’s claim. First, there was only a single defendant, Dr. Ball, on trial for negligence, and no other doctor or health care provider was mentioned in any of the evidence as having been guilty of negligence which caused or contributed to the death of Mr. Hilden. There was no request that any other health care providers be placed on the special jury verdict form. If the negligence of any other doctors or hospital personnel had been a “force” or cause of the death of Mr. Hilden, then their negligence would have been evaluated by the jury even though they had not been made parties to the action. Lasselle v. Special Products Co., 106 Idaho 170, 677 P.2d 483 (1983) (“As stated in Pocatello Industrial Park Co. [v. Steel West, Inc., 101 Idaho 783, 621 P.2d 399] (1980) the reason for the rule is that ‘true apportionment cannot be achieved unless ■ that apportionment includes all tortfeasors guilty of causal negligence either causing or contributing to the occurrence in question, whether or not they are parties to the case.’ ”). The entire thrust of plaintiff’s case was that it was solely the defendant Dr. Ball who breached the local community standard of care by failing to pre-oxygenate Mr. Hilden before inducing anesthesia, which breach was the proximate cause of the death of Mr. Hilden.
Plaintiffs’ case was based upon the testimony of their expert medical witness Dr. Elthrington, who testified that the cause of Mr. Hilden’s cardiac arrest and subsequent death was the failure of Dr. Ball to pre-oxygenate the patient. Dr. Elthrington said:
I think if that patient had been pre-oxygenated from the very beginning of the injections of drugs and allowed that reserve [of oxygen], I think this patient might well have been resuscitated.
*336I’ll go one step further, my patient in my opinion would not have arrested in the first place.
When asked what difference the absence of pre-oxygenation would have made in this case, Dr. Elthrington responded, “I think it made the difference between the patient dying and having a good chance of being resuscitated.” At the conclusion of his testimony, Dr. Elthrington stated:
[I]n my opinion the heart stopped beating because the heart did not have enough oxygen because the patient had no reserves to begin with and those reserves he did have were utilized during the time it took to get air into lungs, and by that time the patient’s heart had died.
The defendant, on the other hand, produced expert medical testimony denying that Dr. Ball had breached the local standard of care by failing to pre-oxygenate the patient Mr. Hilden. In response to the question, “Do you have an opinion as to a reasonable degree of medical certainty whether or not the fact that you did not give oxygen prior to induction caused Robert Hilden’s death,” Dr. Ball testified:
Well, I do not believe that preoxygenation would be significant in this case, because post intubation and actually even post Anectine or anything I was still unable to move air of any quantity worth mentioning. However, had the air been able or oxygen been able to be moved in and out with the bag, then there would have been no problem. And I don’t believe that extra oxygen in the beginning would have altered that at all. The fact that not only immediately post induction, but throughout the next almost well 45 minutes it was still impossible to adequately move air in and out.
The defendant also produced Dr. Klipperdt, an anesthesiologist, who rendered an expert opinion, to a reasonable degree of medical certainty, that the defendant Dr. Ball did not necessarily breach the local standard of care in Burley, Idaho, by failing to preoxygenate this patient. Dr. Klipperdt testified that he did not preoxygenate all of his patients, stating:
The vast majority [that] I do preoxygenate are those who have emergency surgery because they are suspected of having a full stomach having eaten recently and the emergency need to do surgery eliminates the opportunity to allow time to pass for their stomach to empty prior to the surgery. So to summarize if I believe they have food still in their stomach from having eaten recently and there is not enough time for that to digest and pass through the orifice and it’s not likely that it will pass in a given time ... we’ll proceed with preoxygenation in the emergency.
Q. In the obese people that you have put under a general anesthetic, are they all preoxygenated?
A. No they are not.
The plaintiffs did not produce evidence of other multiple “forces” or causes which were themselves sufficient to bring about the death of Mr. Hilden, and which were not related to any act or omission on the part of Dr. Ball. Nor did appellant’s trial counsel argue, either in opening or closing arguments, that there were multiple causes for Mr. Hilden’s death, not all of which were attributable to the defendant Dr. Ball. Rather, Hilden’s counsel asserted, both in opening and closing arguments, that the cause of Hilden’s death was the negligent failure of Dr. Ball to pre-oxygenate Hilden prior to administering general anesthesia and, as a result, Hilden had no oxygen reserve to sustain his heart until his breathing could be supported artificially.
In opening, Hilden’s counsel argued: [The defendant may] disagree with the conclusion, and that conclusion being well, it was acceptable care for Doctor Ball to do things the way he did. [A]nd the proof is going to show that it is never acceptable care not to be prepared for something you know might happen. And it’s never acceptable care to take a gentleman and deprive him of his ability to breathe normally and not take care of his oxygen needs. And consequently you’re going to come to two conclusions, that the care given to this gentleman was substandard and that is why he died.
*337In closing argument, Hilden’s counsel again asserted that by not pre-oxygenating Mr. Hilden the patient was deprived of the oxygen reserves necessary to carry him through the period when he could not breathe for himself and before the intubation and artificial breathing was commenced.
The problem goes to that reserve. The reserve level is so low he couldn’t handle hardly any amount of time without oxygen.
We don’t back off from the fact that the preoperative period is the key. The use of the reserve of the oxygen preoperatively is the key. It’s not just you are saying I should pre[-]oxygenate everybody[.] We are saying that in this circumstance an individual with compromised ventilation deserved a fighting chance.
Dr. Ball’s counsel, in his closing argument, acknowledged the singleness of appellant’s claims:
Now, the plaintiff has said one thing, and one thing only. The plaintiff hasn’t said that general anesthesia was a bad idea. They haven’t said that. They agree with that. They agree that general anesthetic was the way to go in this case. They didn’t say the drugs were improper. Doctor Elthrington testified they were used all the time. They have been used on millions of patients and they still are today. They don’t complain about that. They don’t complain that Doctor Ball got the tube in the trachea. Doctor Elthrington said that is where it was. They don’t say the dosage of the drugs are bad. They said one thing. They said Doctor Ball should have pre-oxygenated this patient, and because he didn’t, this patient died. And that is it. That is what they said.
At the jury instruction conference appellant did not advise the trial court, as they now assert in this Court, that they were contending that there were multiple “forces” or causes of Mr. Hilden’s death, not all of which were attributable to the negligence of the defendant Dr. Ball, and that therefore the standard IDJI No. 230, with its “but for” language, was inappropriate in this case. Although appellants did routinely “object to all of the instructions that were not proposed by us,”3 appellant’s counsel did not apprise the trial court at the jury instruction conference of the claim it is now making on appeal or even mention the proximate cause instruction. Accordingly, the trial court was left to evaluate plaintiff’s case based solely upon its analysis of the evidence admitted at trial, and the claims then being made. Based upon that record, which attempted to place the cause of death solely on Dr. Ball for failure to pre-oxygenate the patient, the trial court understandably chose the standard IDJI Instruction No. 230 as the correct instruction to be given in this case.
The Alaska case relied upon by the appellant, Wilson v. City of Kotzebue, 627 P.2d 623 (Alaska 1981), does not support appellant’s position. The Alaska court in Wilson refused on appeal to subdivide an essentially single-cause case into various multiple “forces” or causes for purposes of determining whether a “but for” type proximate cause instruction should have been given. The court in the Wilson case upheld the giving of a “but for” type proximate cause instruction, stating, “Under Wilson’s theory of the case, but for the city’s various acts of negligence either there would have been no fire or he would not have been injured by it, or his injuries would not have been so severe.” The Alaska court then held that even though there were various acts of negligence alleged to have been committed by the city, there was only a single “force” or cause of the plaintiff’s injury, i.e., the defendant city’s negligence, and therefore a “but for” type proximate cause instruction was the proper instruction. “The exception which we referred to in Abbott does not apply.” “This *338is not such a [multiple cause] case.” 627 P.2d at 680.
Based upon the allegations and the evidence before the trial court, and the statements of counsel, or the lack thereof at the instruction conference, we conclude that the trial court did not err in choosing to instruct the jury using the standard IDJI 230 instruction defining proximate cause.
Accordingly, we adhere to the views expressed in our original opinion.
JOHNSON, BOYLE and McDEVITT, JJ., concur.. This second half of the two part definition of "proximate cause” has been described by Prosser & Keeton as having very little to do with factual causation.
Unlike the fact of causation, with which it is often hopelessly confused, this ["scope of legal responsibility”] is primarily a problem of law. It is sometimes said to depend on whether the conduct has been so significant and important a cause that the defendant should be legally responsible. But both significance and importance turn upon conclusions in terms of legal policy, so that they depend essentially on whether the policy of law will extend the responsibility for the conduct to the consequences which have in fact occurred. Quite often this has been stated, and properly so, as an issue of wjiether the defendant is under any duty to the plaintiff, or whether the duty includes protection against such consequences. This is not a question of causation, or even a question of fact, but far removed from both: and the attempt to deal with it in such terms has led and can lead to utter confusion.
PROSSER AND KEETON ON TORTS § 42, (5th ed. 1984).
. We acknowledge the preeminent position of a trial judge in evaluating such claims. The trial judge presides over all of the proceedings in the trial court, from the beginning where the issues are formulated by pleadings, discovery, pretrial and trial conferences, to the trial where the parties submit evidence to prove their case, and finally the instruction conference with the attorneys and the final arguments to the jury. Because of his participation at each stage of the trial proceedings, the trial judge is in a better position to evaluate the nature of the plaintiffs claims than is a court on appeal judging the proceedings in hindsight from a cold record. Particularly, with regard to the evaluation of the evidence in support of the plaintiffs claim, the trial court is in a unique position to evaluate how that evidence relates to the claims then being made by the litigants. Accordingly, we give substantial deference to the trial court’s evaluation of the issues which result in the court’s instructions to the jury.
. As pointed out in our original opinion, the first part of Instruction No. 4 was plaintiffs requested instruction.