This is an action to recover damages for personal injuries which plaintiff suffered when defendant’s truck collided with plaintiff’s automobile. Plaintiff appeals from a judgment of nonsuit.
At the time of the accident defendant’s truck was in the possession of Prank Lovely, one of defendant’s employees. In the absence of rebutting testimony, this fact would give rise to an inference of agency.① *349The trial court held, however, that the inference was rebutted by the evidence adduced in this case. The evidence rebutting the inference was the uncontradicted testimony of several witnesses for defendant. The issue on appeal is whether there was any evidence other than the uneontradicted testimony of defendant’s witnesses from which the jury could have reasonably inferred that Lovely was acting as defendant’s servant at the time of the accident.
We begin with the well-established principle that the credibility of witnesses is ordinarily to be determined by the jury. We carefully examined this generalization in Richard v. Ellis, 230 Or 46, 51, 368 P2d 396 (1962), observing that “[i]n some cases an issue upon which there is uncontradicted testimony is properly submitted to the jury; on the other hand in some cases the question of the credibility of a witness is properly withheld from the jury.” We re-asserted the test adopted in Wiebe v. Seely, Administrator, 215 Or 331, 343-344, 335 P2d 379 (1958),② and elaborated upon it by noting two important factors to be considered in deciding whether the jury should be permitted to draw inferences contrary to the uncontradicted testimony. The factors were (1) the availa*350bility of evidence to contradict the witness’s statement, and (2) the likelihood that the witness’s interest in the litigation may tempt him to testify falsely.
The general standard to be applied in determining whether a case should be submitted to the jury is well stated in Jerke v. Belmont State Bank, 54 S D 446, 456, 223 NW 585 (1929) and endorsed by 9 Wig-more on Evidence, § 2495, p. 306 (1940) as expounding “the correct principle with inexorable logic.” The court, after noting that “We are too often prone to exaggerate the powers and privileges of a jury as a trier of facts,” reminds us that “the general superintendence and control of the court and all its machinery, including the jury, rests with the judge, and [that] it is fundamental that an issue arising between litigants must be tried by a general, rational, or reasoning process, both as to the ascertaining of facts and the application of the law.” Going on, the court says:
“* * * Before there is anything for submission to the jury, the evidence offered as to the ultimate facts must be such that the application of normal intellectual faculties thereto might by the customary and normal processes of reasoning arrive at different judgments or conclusions. *****
“Jurors do not determine all questions of ultimate fact, even in jury cases. They determine the existence or nonexistence of those facts, and those only, with reference to the existence of which the judgment of reasonable men might differ as a result of their intellectual faculties to the evidence.” 54 S D at 457-458.
The court, turning to the specific question of the effect to be given the factor of credibility, said:
“* * * But the entry of the factor of eredibility, either one way or the other, can make no difference in the operation of the fundamental *351principle which, necessarily underlies the direction of verdicts in all cases. The question of whether reasonable minds could arrive by reasoning process at more than one opinion or conclusion is always a question for the judge. The entry of the factor of credibility means simply the existence of one more item upon which the intellectual faculties are to operate. * * *
“A jury has no greater or better right to act arbitrarily or unreasonably in forming a judgment or opinion as to whether or not a witness speaks the truth than it has to act unreasonably in arriving at any other opinion or conclusion. Forming an opinion as to credibility should be just as much a process of rationalization or reasoning from the data presented in the light of human experience as the formation of any other opinion or judgment in a court, and this has always been recognized by the great majority of the courts, and the proposition, subject to various qualifications, has been laid down in some such phrasing as that ‘the positive testimony of a disinterested, uncontradicted witness cannot be arbitrarily or capriciously disregarded by the jury.’ ” 54 S D at 459-460.
With this general background of the applicable principles, we now turn to a more detailed statement of the facts.
Defendant was engaged in the roofing business, which was conducted along with a retail lumber business. Frank Lovely was employed by defendant as foreman of its roofing crew. Lovely used a pick-up truck owned by defendant in carrying out his duties as foreman of the crew. According to the testimony of Lovely and John Whittemore, former manager of defendant’s business, Lovely was permitted to keep the pick-up truck in his possession, not only when he was performing his regular daily duties but also after *352regular working hours. Lovely provided a garage for the truck and was permitted to use the truck for his own personal use whenever it was not being used for his employer’s purposes. Defendant provided all the fuel for the pick-up.
During the evening hours Lovely was subject to call by defendant in the event of an emergency requiring the temporary repair of a roof. Por this purpose, the truck carried a few tools and supplies belonging to defendant.
On the evening of the accident Lovely had driven the truck over to the residence of Robert Hansen, who was also employed by defendant and worked on Lovely’s roofing crew. Lovely parked the truck on the street in front of Hansen’s house. While the truck was unattended it rolled down the street and collided with plaintiff’s automobile, causing the personal injuries for which this action is brought. Both Lovely and Hansen testified that the purpose of Lovely’s visit was to pick up Hansen, who by previous arrangement had been employed by Lovely to help Lovely remodel one of his own rental houses.
Upon examination by plaintiff’s counsel, Hansen testified as follows:
“Q All right. On the evening we’re talking about, Mr. Lovely came to your door, knocked, you went to the door; right?
“A Yes.
“Q All right. What happened then?
“A He came in. I got my coat and hat.
“Q Well, what did he say when he came in?
“A Well, he asked me if I was ready to go. I was going out to his place to help him put up some sheet rock on his house.
*353“Q And did lie ask you the status of the job you had been working on for Van Petten that day?
“A No.
((^ ^
“Q Now, you and I talked about this, didn’t we, Mr. Hansen?
“A Yes.
“Q And you told me what had happened there, didn’t you?
“A Yes.
“Q Didn’t you tell me that he asked you if you had finished the job that you were doing for Van Petten that day?
“[Objection]
“Q You tell us all that was said there, Mr. Hansen, when Mr. Lovely came to your place that night.
“A It’s been quite awhile ago. He came in, asked me, — He came in. He asked me if I was ready to go. I said, ‘Yes, I’ll get my coat.’ I got my coat and hat. When we started out, he said, ‘Did you get done with your job?’
“THE COURT: * * * What did he say?
“THE WITNESS: He said was I about ready to go. I said, ‘Yes.’ I got my coat and hat. As we was going out, he said, ‘How did you fellows do today?’
“THE COURT: What?
“THE WITNESS: ‘How did you fellows do today?’
“BYMR. CATER:
“Q What did he have reference to, Mr. Hansen?
“A That could cover a lot of things.
*354“Q Yeah, but yoxi knew whát he meant, didn’t you?
“A Yes, I knew what he meant. The job we were working on, he asked me how we had done. That was all.
“Q This was the work that you did for Van Petten Lumber Company that day?
“A Yes.
“Q That he was asking yon about?
“A Yes.
ÍÍ* * * *
“Q Had he [Lovely] been present on that roofing job that you were working on for Van Petten on that particular day?
“A He was in the morning.
“Q Then in the afternoon, he wasn’t there?
“A Not to my knowledge.
“Q So he was asking you what happened in the afternoon; is that right?
“[Objection sustained]
“Q What did yon tell him in answer to his question?
“A I never answered him.
“ Q You never answered him ?
“A No.
“Q How come?
“A Because there was a lady at the door. As we walked out, we met this lady there.”
Upon examination by defendant’s counsel, Hansen testified that Lovely had employed him to work for Lovely in remodelling a house owed by Lovely, for which Hansen was to be paid. On previous occasions Hansen had worked for Lovely on a similar arrangement and was paid by check.
In describing the visit to Hansen’s home, Lovely, *355when examined by plaintiff’s counsel,, testified as follows:
“Q What did you say to Mr. Hansen?
“A Asked him if he was ready to go.
“Q And what else ?
“A I don’t recall anything.
“Q Did you ask him about the condition or progress of the job that he’d been working on for van Petten that day?
“A Not that I recall.
“Q You don’t recall that ?
“A No, sir, I don’t remember asking bim of anything.
“Q Did you hear him say that you asked him how he got along with the job that day?
“A I don’t remember of it.”
Defendant’s counsel elicited the following testimony:
“Q * * * What was your arrangement with Mr. Hansen, particularly? Why were you going to pick him up ?
“A To help me on one of my houses.
“Q What were you doing on your houses ?
“A Carl, I can’t tell you exactly what we were doing cause I was remodeling three houses at one time and it is kind of hard to recall.
“Q These were rental houses, rental houses that you owned at the time?
“A Eight.
“Q And you were doing something with respect to remodeling?
“A I had them moved in and I was remodeling, getting them ready to rent.”
We must decide whether this evidence is sufficient to support an inference that Lovely was acting in the course of his employment for defendant at the *356time of the accident. Stated differently, the question is whether the inference of agency arising from Lovely’s possession of the truck owned by defendant was rebutted by evidence that tends to show that Lovely was using the truck for personal purposes.
We have held that to overcome the inference of agency arising from possession by one not the owner, the evidence must be clear and convincing.③ And it should be noted that the inference of agency is strengthened in the present case by the fact that the vehicle is a truck driven by an employee of the owner.④ On the other hand, it is also important to take into account Mr. Justice Lusk’s observation in Bunnell v. Parelius, 166 Or 174, 185, 111 P2d 88 (1941), that “the inference of agency from the fact of ownership is a slender reed upon which to lean; a species of evidence so weak that in any intelligent system of law it must yield to facts established by evidence which only an arbitrary judgment would reject.”
We are also to bear in mind that the inference may be rebutted by testimony that comes from an interested witness. ⑤ And, as we have previously noted, we must take into consideration the factors isolated in Rickard v. Ellis, supra, relating to the access of the parties to the evidence tending to support or contra-*357diet the inference of agency arising out of the fact of ownership.
Looking first at the alleged oral bailment under which Lovely was entitled to use the truck after working hours for his own personal purposes, we have the uncontradieted testimony of Lovely and also that of John Whittemore. If it is said that the jury could disbelieve Lovely because his interest in retaining his employment might tempt him to testify falsely, it can also be said that his testimony exculpating defendant served to identify Lovely as the person at fault. But even if Lovely’s testimony is discredited because of his interest, there is still the testimony of John Whittemore, defendant’s former manager, testimony which cannot be attacked upon the ground that it was self-serving, because at the time he testified he was not employed by defendant but was engaged in his own business. Because Whittemore was engaged in a business which competed with defendant’s the temptation, if any, would be to testify unfavorably to defendant’s interest. And if, in fact, there was no bailment to Lovely for personal use, plaintiff was not without means of disproving it.
In the face of this evidence, the members of the jury could not conclude that there was no bailment simply by deciding that they would not believe either Lovely or Whittemore. This would violate the principle explained in Jerke v. Belmont State Bank, supra, that the jury must reach its conclusions “by a process of rationalization and judgment, and by the application of the thinking faculties of the human mind to the evidence.” (54 S D at 456.) This uncontradieted evidence of a bailment would, then, rebut the inference of agency from the fact of ownership in the absence *358of additional evidence from which, it conld be inferred that tbe truck was actually being used at the time of the accident for the employer’s business purposes rather than for Lovely’s own personal purposes.
Plaintiff would have us hold that because Lovely was on call during the evenings to repair roofs for defendant, any use of the truck by Lovely would be in the course of his employment. We reject this characterization of the transaction. It is our view that during off hours Lovely would assume his status as an employee only when he was actually using the truck to carry out a specific job for his employer.
Plaintiff then argues that there was evidence to show that at the time of the accident Lovely was using the truck for defendant’s purpose. She contends that the jury could find that Lovely’s purpose in visiting Hansen on the evening of the accident was to check with Hansen on the progress of that day’s work by the roofing crew. To support this possible interpretation of Lovely’s visit, plaintiff relies upon the conversation between Lovely and Hansen at the latter’s home just before the accident, pointing specifically to Lovely’s inquiries: “Did you get done with your job” and “How did you fellows do today.” It is argued that these inquiries could be regarded by the jury as evidence that Lovely went to Hansen’s home to serve the interest of his employer by ascertaining what the roofing crew did during the day. Plaintiff’s counsel attempted to strengthen the alleged inference by getting Lovely to admit that he sometimes checked with men on the roofing crew after hours as to the progress of their work.⑥
*359Considering the context in which Lovely’s inquiries were made, it would be gross speculation for the jury to conclude that the objective of Lovely’s visit was to carry on his work for defendant.
In appraising the uncontradicted testimony explaining Lovely’s visit as having been prompted by a personal objective, it is important to note that at the time Hansen testified he was not employed by defendant. Quite to the contrary, he was carrying on his own roofing business presumably in competition with defendant’s business. There was not therefore “the likelihood that the witness’s interest in the litigation * * * [would] tempt him to testify falsely,” which we isolated as an important factor in Rickard v. Ellis, supra 230 Or at 52.
Moreover, there was available to plaintiff the opportunity to contradict the witnesses’ statement if it was false, another factor noted in Rickard v. Ellis, supra. Lovely and Hansen testified that Hansen had been previously employed by Lovely to work on the *360latter’s houses. Payment for these services was by check. If, on demand, Lovely could not have produced the cancelled checks, there would then have been reason to disbelieve Lovely’s explanation for visiting Hansen.
We have previously noted that Whittemore was also in a business in competition with the business of defendant and therefore had no reason to give false testimony in favor of defendant. It would not have been reasonable for the jury to disbelieve Whittemore’s testimony as to the nature of the bailment of the truck.
We have, then, as we had in Judson v. Bee Hive Auto Service Co., supra, evidence of a bailment, uncontradicted by any evidence adduced by plaintiff. The jury could not have concluded on a rational basis that Lovely was in the course of his employment for defendant at the time of the accident.
The judgment is affirmed.
Judson v. Bee Hive Auto Service Co., 136 Or 1, 294 P 588, 297 P 1050, 74 ALR 944 (1931); Kowaleski v. Kowaleski, 235 Or 454, 385 P2d 611 (1963).
The test was adopted from Ferdinand v. Agricultural Ins. Co., 22 NJ 482, 126 A2d 323, 62 ALR2d 1179 (1956) which stated it as follows: “ * * Where men of reason and fairness may entertain differing views as to the truth of testimony, whether it be uncontradicted, uncontroverted or even undisputed, evidence of such a character is for the jury. * * * [Citing cases]. But when the testimony of witnesses, interested in the event or otherwise, is clear and convincing, not incredible in the light of general knowledge and common experience, not extraordinary, not contradicted in any way by witnesses or circumstances, and so plain and complete that disbelief of the story could not reasonably arise in the rational process of an ordinarily intelligent mind, then a question has been presented for the court to decide and not the jury.’ ” -230 Or at 51, 368 P2d at 398.
Brown v. Fields, 160 Or 23, 29, 83 P2d 144 (1938). The court held that the question of agency is to be submitted to the jury unless “the only reasonable deduction to be made from the evidence is that the automobile was not being driven in furtherance of the interests of the owner * *
Cf., Jasper v. Wells, 173 Or 114, 130, 144 P2d 505 (1943).
Miller’s Will (Luis v. Muhrback), 49 Or 452, 464, 90- P 1002, 124 Am St Rep 1051 (1907): “The testimony of witnesses is not to be disregarded merely because they are interested in the result. Other reasons for discrediting them must appear.” See also, Miller v. Service and Sales, Inc., 149 11, 38 P2d 995, 96 ALR 628 (1934); 62 ALR2d 1198.
“Q From time to time in. your work for Van Petten Lum*359ber Company, it was the custom for you to check with your men on your crew or crews, some evenings, to see how they were getting along wasn’t it?
“A Not very often, Charlie. I generally had my work lined out in the morning. I consulted my crews in the morning because there were lots of times I would be out where I wouldn’t see my crew when they come in of an evening.
“Q So you would have to check with them?
“A Not of a night.
“Q But you did, didn’t you?
“[Objection] * * *
“Q You did sometimes contact the employees and check with them in the evening as to the progress of the job they were working on?
“A I have an idea—I don’t ever remember running one of them down to find out what he done, but I have an idea I have asked some questions when they come in or something like that.”