This was an action to recover damages for personal injuries alleged to have been incurred by plaintiff when his automobile was struck in the rear by defendant’s automobile. Plaintiff appeals from a judgment entered on a verdict for defendant.
Plaintiff stopped his automobile at an intersection showing a red light to his lane of traffic. Defendant struck plaintiff’s automobile in the rear. Plaintiff alleges that as a result of the collision he suffered back, arm and neck injuries which were painful and as a result of which he avoided doing anything of a strenuous nature. Defendant’s insurer, Allstate Insurance Company, employed Vincent Castrapel, a private investigator, to make an undercover surveillance of plaintiff’s activities prior to trial. In carrying out this assignment, Castrapel took moving pictures and recorded other observations of plaintiff’s conduct which showed that plaintiff had done various things which involved strenuous activity. When Castrapel testified to this effect plaintiff, in an effort to prove bias, sought to show that Castrapel was hired by Allstate Insurance Company to make the surveillance; that he was paid $400 for his services, and that he was regularly employed by insurance companies to make undercover surveillances. The trial court refused to allow plaintiff to introduce such evidence, whereupon plaintiff made an offer of proof. On appeal, plaintiff assigns as error the trial court’s refusal to receive evidence identifying Allstate as Castrapel’s employer. Castrapel did testify that he was engaged in the business of making investigations for "firms or lawyers”; that he had been employed on defendant’s behalf to make the investigation in this case, and that he was paid $473 for his services. Plaintiff argues that the jury should be told in addition that Castrapel was hired and paid by defendant’s insurer.
The testimony that Castrapel was engaged in the business of making investigations and was paid to *528make the investigation on behalf of defendant revealed to the jury the facts from which bias could be inferred. To draw this inference it was not necessary for the jury to know that an insurance company was the witness’ employer. Plaintiff argues that the jury could regard the witness as having a greater zeal to slant his testimony in favor of defendant out of a desire to get further business from Allstate. Plaintiff could have adduced this additional evidence of potential bias without revealing defendant’s insurance coverage. Our ruling does not preclude plaintiff from introducing evidence that most of the witness’ business was for the same group of "firms and lawyers” or that the witness seeks repeat business "by showing them (his) skill and (his) efforts on their behalf.” Mention of an insurance company adds nothing to the inference. Therefore, the evidence would still be inadmissible on the ground that the need to avoid prejudice which could result from the disclosure of insurance coverage1 would outweigh the need to strengthen an inference which was already permissible upon the basis of other evidence. We hold, therefore, that the trial court did not err in rejecting the proffered evidence.
Plaintiff also assigns as error the following instruction to the jury:
"* * * And in fixing an amount of damages, you are to consider not only what might be right for an injured person to receive in order to afford just compensation, but also what it is just to compel the other party to pay.”
Plaintiff took exception to this instruction on the ground that it invited the jury to consider defendant’s financial circumstances in arriving at the amount of damages which should be assessed.2 Defendant coun*529ters with the argument that the instruction says no more than previous Oregon cases have said in connection with the assessment of a fair measure of damages. Thus in Hansen v. Oregon-Wash. R.& N. Co., 97 Or 190, 201, 188 P 963, 191 P 655 (1920) the court said:
"* * * While the fundamental rule of the law is to award compensation, yet rules for ascertaining the amount of compensation to be awarded are formed with reference to the just rights of both parties, and the standard fixed for estimating damages ought to be determined not only by what might be right for an injured person to receive in order to afford just compensation, but also by what is just to compel the other party to pay % * »
The foregoing statement was quoted in Oregon Mutual Fire Ins. Co. v. Mathis, 215 Or 218, 223, 334 P2d 186 (1959), and again in Mock v. Terry, 251 Or 511, 513, 446 P2d 514 (1968). All of these cases involved the measure of damages for injury to property, and the reference to what was just to compel the defendant to pay clearly related to the manner of measuring a monetary loss when personal property is damaged; these cases did not purport to say that the ability of the defendant to pay should be considered in assessing damages.
Defendant argues that the instruction given in the present case does not carry the suggestion that defendant’s financial condition is to be considered by the jury in determining the amount of damages which should be allowed, and that the instruction amounted only to a statement that compensation for damages sustained "must be in an amount that is right to receive and right to pay.” It may be conceded that the instruction could be interpreted to mean that what is "just to compel the other party to pay” is never less than what is "just compensation” to the plaintiff. But the instruction would still be prejudicial and reversible error if it can also be interpreted to bear the meaning which plaintiff attributes to it. An ambiguous instruction, equally capable of a correct or an incorrect *530statement of the law, is just as vulnerable to attack on appeal as one which is unambiguously incorrect if it is prejudicial. We think that the instruction could have prejudiced plaintiff’s chance of recovery in this case and therefore the judgment must be reversed.
In his dissenting opinion Justice Tongue chides the author of the majority opinion for having written an "eloquent” statement in a specially concurring opinion in Johnson v. Hansen, 237 Or 1, 9, 389 P2d 330, 390 P2d 611 (1964), to the effect that the prejudicial effect of the mention of insurance before a jury is largely a thing of the past, a view which is irreconcilable with the position now taken in the present case. It should be obvious that the liberty a judge has to express his dissenting views does not give him the license when speaking for the majority of the court to use those unaccepted views as a basis for the court’s opinion.
Justice Tongue also chides the author of the majority opinion for reasoning "without reference to any legal authorities, much less to the previous decisions of this court” that an inference was already permissible upon the basis of other evidence in this case. It is difficult to understand why any support from other authorities is needed to explain the ground for drawing a simple inference which rests upon the facts of the particular case before the court.3
Reversed and remanded for a new trial.
Even if the prejudice "is not likely to be very great.” See Johnson v. Hansen, 237 Or 1 at 18, 389 P2d 330, 390 P2d 611 (1964).
Plaintiff contends that the jury could have been influenced to deny recovery by the fact that defendant "was a married woman of modest means with three children and an old automobile * * * [1966 Volkswagen Beetle].”
In light of the criticism which has been levelled at long opinions, judges should err on the side of restraint in citing and quoting from authorities which do not illuminate the court’s reasoning.