dissenting:
I dissent on two counts. First, I disagree with the majority’s characterization of the hearing officer’s findings on the cause of the claimant’s permanent and total disability as “ultimate conclusions of fact” and therefore subject to reversal by the Industrial Commission under section 8-53-106(2)(b), 3 C.R.S. (1982 Supp.), ch. 86, sec. 2, 1981 Colo.Sess. Laws 476-77.1 Second, I cannot accept the majority’s construction of section 8-51-106(l)(a), 3 C.R.S. (1983 Supp.), to preclude the payment of compensation benefits by the Subsequent Injury Fund when nonindustrial factors contribute to the claimant’s permanent and total disability.
I.
The fact that the claimant is entitled to total and permanent disability benefits is not disputed by any party to this appeal. The only dispute is whether the claimant’s last employer, the City and County of Denver, is liable for payment of the entire award of permanent and total disability, or, instead, is liable for that percentage of permanent disability attributable to the claimant’s last industrial accident on January 18, 1980, with the Subsequent Injury Fund being liable for the balance of permanent and total disability payments.
The hearing officer found, as relevant here, (1) that the claimant sustained a twenty-five percent permanent disability as the result of the industrial accident on January 18, 1980, while he was employed by the City and County of Denver, and (2) that the claimant had previously sustained permanent partial disability as a result of prior industrial accidents. From these findings the hearing officer concluded that “[t]he combined industrial disabilities render the claimant permanently and totally incapable of steady gainful employment and incapa*205ble of rehabilitation to steady gainful employment,” with the result that the Subsequent Injury Fund was liable for the payment of that part of permanent and total disability over and above the claimant’s twenty-five percent permanent partial disability attributable to the industrial accident on January 18, 1980.
On review the Industrial Commission made additional factual findings. It found that the cause of the claimant’s permanent and total disability was attributable not only to the industrial accidents to which the hearing officer referred in his findings but also to several other nonindustrial conditions, such as asthma, glaucoma, obesity, and arthritis. Based on these additional factual findings, the commission concluded:
that claimant has suffered permanent total disability from a combination of industrial injuries and other conditions of health and afflictions, which disability was not caused exclusively by the first injury combined with the subsequent injury ... and that the Subsequent Injury Fund is not liable upon the claim.
Consequently, under the commission’s order, the City and County of Denver, the last employer, must bear the total burden of paying permanent and total disability benefits to the claimant. The court of appeals affirmed the commission’s order, holding that the additional findings by the commission were ultimate findings of fact within the commission’s authority under section 8-51-106(l)(a) and that the commission’s interpretation of the statutory liability of the Subsequent Injury Fund under section 8-51-106(l)(a) was correct.
II.
In contrast to the majority, I view the hearing officer’s finding on the actual causation of the claimant’s permanent and total disability as a finding of evidentiary fact and thus binding on the commission under section 8-53-106(l)(a). Findings of evidentiary fact involve the raw, historical data underlying the controversy. deKoevend v. Board of Education, 688 P.2d 219, 226 (Colo.1984); Lee v. State Board of Dental Examiners, 654 P.2d 839, 844 (Colo.1982); Ricci v. Davis, 627 P.2d 1111, 1118 (Colo.1981); Blair v. Lovett, 196 Colo. 118, 124, n. 13, 582 P.2d 668, 672, n. 13 (1978); see also Industrial Commission v. Jones, 688 P.2d 1116, 1120 (Colo.1984) (Quinn, J., dissenting). In the order of nature, actual causation plays a central role as a precondition of legal redress. Once actual cause is established, legal causation must then be determined. In a worker’s compensation case, this means that the claimant must demonstrate the industrial accident causing his disability was a sufficient legal cause to justify the granting of legal redress. The determination of legal cause involves the application of legal standards in order to determine the rights and liabilities of the parties. deKoevend, 688 P.2d at 224; Lee, 654 P.2d at 844; Ricci, 627 P.2d at 1118; Blair, 196 Colo. at 124, n. 13, 582 P.2d at 672, n. 13; R & R Well Service Co. v. Industrial Commission, 658 P.2d 1389, 1391 (Colo.App.1983); see also Jones, 688 P.2d at 1122 (Quinn, J., dissenting). These legal standards are based on statutory or jurisprudential policy considerations underlying the imposition of ultimate legal liability and, as such, are substantively and analytically distinct from the raw, historical data inherent in a finding of the actual causation of a worker’s disability. Cases involving such statutory standards as “proximate” and “intervening” cause, “arising out of employment,” and “the course of employment” point up the policy considerations necessarily applicable in resolving questions of legal cause and compensable consequences in worker’s compensation law. E.g., Standard Metals Corp. v. Ball, 172 Colo. 510, 474 P.2d 622 (1970); Johnson v. Industrial Commission, 148 Colo. 561, 366 P.2d 864 (1961); Alexander Co. v. Industrial Commission, 136 Colo. 486, 319 P.2d 1074 (1957); see generally 1 A. Larson, The Law of Workmen’s Compensation §§ 6.10 to 6.60, 13.-11, 13.12 (1984).
Section 8-53-106(2)(b) prohibits the commission from setting aside a hearing officer’s findings of evidentiary fact unless those findings are “contrary to the weight *206of the evidence.” The commission in this case made no determination that the hearing officer’s findings on the actual cause of the claimant’s permanent total disability were contrary to the weight of the evidence. Instead, the commission made extensive factual findings of its own on these matters. Section 8-53-106(2)(b), in my view, does not authorize the commission to engage in the type of independent and far-ranging factual inquiry that it pursued in this case. The commission’s review function “is predicated on the assumption that the [hearing officer] is in the best position to resolve factual questions.” Jones, 688 P.2d at 1122 (Quinn, J., dissenting). This assumption is eminently reasonable because resolution of factual questions will often turn on the hearing officer’s assessment of the credibility of witnesses testifying before him and his allocation of differing weight to their respective testimony. These are functions which the commission, in its review of the “record,” cannot effectively perform.
While I agree that the hearing officer’s determination of the Subsequent Injury Fund liability was an ultimate conclusion, since it was a legal conclusion that resolved the rights and liabilities of the parties, I believe it was inappropriate for the commission to make those evidentiary findings that were essential to a correct resolution of this ultimate issue. The appropriate course for the commission, in my opinion, was to remand the case to the hearing officer for any additional factual findings necessary to correctly determine the liability of the Subsequent Injury Fund for the claimant’s permanent and total disability.
III.
I also disagree with the majority’s holding that section 8-51-106(l)(a) precludes Subsequent Injury Fund liability when nonindustrial factors contribute to the claimant’s permanent and total disability. In a worker’s compensation proceeding a claimant need only establish by a preponderance of the evidence that a disability resulted from or was precipitated by an industrial accident. Public Service Co. v. Industrial Commission, 189 Colo. 153, 538 P.2d 430 (1975); Industrial Commission v. Royal Indemnity Co., 124 Colo. 210, 236 P.2d 293 (1951). We have never required an employee to establish that the causal nexus between an industrial accident and an ensuing industrial disability was such as to eliminate all nonindustrial factors. “Compensation is not dependent on the state of an employee’s health or his freedom from weakness or latent tendency.” Industrial Commission v. Newton Co., 135 Colo. 594, 601, 314 P.2d 297, 301 (1957). Rather, once it is determined that an injury arose out of and in the course of employment, “the results flowing proximately and naturally therefrom come under the aegis of the statute.” Standard Metals Corp. v. Ball, 172 Colo. 510, 515, 474 P.2d 622, 625 (1970), quoting Vanadium Corp. v. Sargent, 134 Colo. 555, 566, 307 P.2d 454, 461 (1957). I see no reason to adopt a different standard of causation for purposes of determining Subsequent Injury Fund liability. In many cases nonindustrial factors might well contribute in some way to a worker’s permanent and total disability, but these nonindustrial factors, by themselves, are not such as to render the worker permanently and totally disabled in the absence of the ensuing industrial accident.
I would impose Subsequent Injury Fund liability whenever it is demonstrated that the subsequent industrial disability was a substantial factor in rendering the employee permanently and totally incapable of steady gainful employment and incapable of employment rehabilitation. This construction comports with the statutory goal of Subsequent Injury Fund liability, which is to “enhance the opportunities for employment for partially disabled persons.” Horizon Land Corp. v. Industrial Commission, 34 Colo.App. 178, 181, 524 P.2d 638, 640 (1974). Without Subsequent Injury Fund protection, employers will naturally be reluctant to hire persons who suffer from industrial and nonindustrial disabilities because, as this case demonstrates, the last employer' will be liable for permanent and total compensation benefits, notwith*207standing the employee’s preexisting partial industrial disability, in the event the employee sustains an industrial accident and is thereafter permanently and totally incapable of steady gainful employment and incapable of employment rehabilitation. The majority, by conditioning Subsequent Injury Fund liability on a demonstration that nonindustrial factors in no way contributed to permanent and total disability, puts the last potential employer on notice that he or she assumes a substantial economic risk by hiring someone who suffers from both industrial and nonindustrial disabilities. The resulting diminution in employment opportunities for those suffering the joint consequences of industrial and nonindustrial disabilities is, in my view, the very antithesis of what section 8-51-106(l)(a) seeks to accomplish.
I would reverse the judgment of the court of appeals and hold that the Subsequent Injury Fund is liable for the total and permanent disability benefits in excess of the twenty-five percent disability attributable to the industrial accident of January 18,1980.
. Article 53 of the Workmen's Compensation Act was repealed and reenacted in 1983. §§ 8-53-101 to 129, 3 C.R.S. (1983 Supp.). Statutory references in this dissent are to those provisions applicable to the proceedings in this case.