No, I don't mean that. I read your query a few days ago and have been periodically trying and failing to imagine where you might get that meaning. I think the language difficulty is maybe insuperable. However, while puzzling, I began to be disturbed by my own wording, which was -- in post #126: "not adequately grounded in evidence to require checking out for truth or falsity". The problem I'm seeing is that "require" could imply something I don't mean, in both directions. It might seem to imply that one is required to check out the truth or falsity of all assertions or hypotheses which are presented with sufficient evidence. But doing such extensive checking would be an impossibly prodigous task. Instead what's required for responsible epistemology is an understanding in principle of how testing can be done and reason to think that it has been done with assertions or hypotheses one accepts as definitely or provisionally true. In the daily course of events, with mundane statements, such checking is made so quickly as often not to be noticed. On the other hand, my wording might seem to imply that there's never a requirement to check assertions or hypotheses which aren't "adequately grounded in evidence." (An aside: I'm aware that what counts as "adequately grounded" can sometimes be a judgment call and debatable.) There are cases where scrutiny is important despite a lack of supporting evidence. Depends on what's at stake in accepting the assertion or hypothesis as if it were supported. For example, the extensive abritrary claims made in the anthropogenic global warming issue can lead to and have led to expensive policy decisions, along with harm to the integrity of scientific procedure. So drawing attention to the arbitrariness is important. An example of general importance for people interested in Objectivism is Rand's habit of making ostensively factual assertions which she didn't support. An interesting project would be to try to do a count of the number of such assertions in her writings, starting with the major claim in Galt's Speech that "man is a being of volitional consciousness." An instance I've been thinking about recently, since I've been rereading Robert Cambell's essay "The Peikovian Doctrine of the Arbitrary Assertion," comes from Rand's last Ford Hall Forum talk, "The Age of Mediocrity," and is quoted in Robert's essay (pg. 100): What is Rand's evidence for the "psychologizing" (by her own definition) claim in the last sentence? How would she know that the reasons given by people who want creationist accounts of species origins to be included in school curricula aren't sincere reasons? She provides no indication. Likewise, she supplies no indicative hint regarding where she'd "read a lot of valid evidence to support" the theory of evolution. Citing some sources by name wouldn't have added that much length to the statement and would have provided a degree of basis for listeners/readers to have a clue as to what she was taking to be "valid evidence." Also, we can't really tell even what she means by "the theory of evolution," that theory not being monolithic. Because of examples like the above -- ones in which there's reason to consider claims which are "arbitrary" by my meaning -- I think a better way of stating that meaning would be: "not adequately grounded in evidence to merit taking seriously as a truth claim". One might have reason to take the claim seriously because of the context in which it's made despite its not having enough evidential support provided to merit its being taken seriously. Ellen Leonid: "Do you mean that any assertion could be checked for truth or falsity, even if such an assertion doesn't pertain to existence?" Helen: "No, I don't mean that." So in fact you have no argument with Peikoff. You just don't want to call such assertions by the name "arbitrary". But that already matter of semantics. As far as I concern , the problem is not which assertions one should check but which assertions could be dismissed or accepted without any further investigation. There are two kinds of them-1. An arbitrary assertions which evidently defy axioms, logic, proven knowledge and common sense. They should be rejected on the blink of eye. 2. The self evident axiomatic truths-like " man is volitional being", or "man is conscious being" or " existence exists". They cannot be proved, since all proves are based on them. Their rejection is self-refuting and they should be accepted without any further investigation. A substitution of scientific theory, no matter how incomplete it is by religious belief is an attack on the man's mind by definition. Why you call it " "psychologizing"? And man-made global warming hypothesis is not arbitrary by any means. As a matter of fact it has been refuted as false and by definition one cannot refute arbitrary assertion.