What is the preponderance test in the context of a personal injury claim?

In Smith v. Smith, (1952) 1952 CanLII 3 (SCC), 2 S.C.R. 312, Justice Cartwright articulated the test as follows: “That civil cases may be proved by a preponderance of evidence or that a finding in such cases may be made upon the basis of a preponderance of probability and I do not propose to attempt a more precise statement of the rule. I wish however to emphasize that in every civil action before the tribunal can safely find the affirmative of an issue of fact required to be proved it must be reasonably satisfied and whether or not it will be so satisfied must depend upon the totality of the circumstances on which his judgment is formed including the gravity of the consequences of the finding.”