The Logical Atheist

 [A]theism was a narrative possibility within Greek myth. A world without gods could be imagined. The possibility that the Olympian gods might cease to exist (or at least to hold power over the cosmos, which amounts to the same thing) was built into the Greeks' story-world. --Tim Whitmarsh, Battling the Gods: Atheism in the Ancient World

 [W]hy should we believe that it is our flourishing [and all it implies about treating others justly] rather than our bare survival that serves as our natural end and so constitutes our self-interest?... [O]n an Aristotelian conception of rationality, one may legitimately take the fact that a goal of flourishing coheres better than a goal of bare survival with our other moral beliefs as a sufficient (though defeasible) justification for believing that flourishing rather than bare survival is our natural end.... [Philosophers such as J. L. Mackie and Ayn Rand] would no doubt object strenuously to the idea of using premises about value to derive conclusions about human nature. But for the Aristotelian, once gain, the growth of knowledge is not a matter of rigid hierarchies but of networks of mutual adjustment, and no privileged class of beliefs holds absolute veto power over beliefs of another class. Hence, we are justified in taking the greater moral appeal of flourishing survival a...

Atheist call-in show hosts like to glibly dismiss some theistic callers as guilty of using the  argumentum ad populum ; that's the claim that a proposition must be true because lots of people believe it to be true. This is considered an informal fallacy  and a fallacy of relevance rather than a formal, or logical, fallacy. But is it really a fallacy? It depends, as we'll see. I'll say right at the top that no less a thinker than Aristotle held that our knowledge is and should be chock full of endoxa , which is Greek for reputable beliefs that almost all people hold without having personally confirmed them. Oops, by dropping Aristotle's name, did I just commit the fallacy of the argument from authority  ( argumentum ab auctoritate ) ? We'll see. When I said above that "it depends," part of what I meant is that it depends on how we phrase the alleged fallacy. "That most everyone believes X is true proves that X is true" is clearly fallacious. But h...

Does rejection of God-based morality--that is, commandments from really on high--leave utilitarianism as the only reasonable approach to ethics? Some atheists think so. Let's start with the definition. Utilitarianism holds that we ought to pursue the greatest happiness/pleasure/good for the greatest number. It sounds reasonable and simple enough, but philosophical critiques of utilitarianism abound. I'll briefly touch on a few points. We could begin by asking why that ought to be our goal. Is this a subjective preference, or can an objective case be made? If it's subjective, then why that one rather than something else? We may wonder whether it's a problem for the theory that people have different ideas about happiness and pleasure. To pick an extreme example, think of the masochists and sadists. Do they count? And do only people count? Moreover, isn't it possible that the two parts of the principle might conflict? Why the greatest happiness for the greatest number?...

By free-thinking I mean the use of the understanding in endeavoring to find out the meaning of any proposition whatsoever, in considering the nature of the evidence for or against it, and in judging of it according to the seeming force or weakness of the evidence.  --Anthony Collins, Discourse of Free-Thinking , 1713 

The Ontological Argument maintains that the existence of an absolutely necessary being cannot be denied without self-contradiction. This concept of God, Kant says, is logically possible (i.e., it does not contain a contradiction), but we can never establish that something [exists] from a mere analysis of the corresponding concept. Real  possibility can never be inferred from logical  possibility. Indeed, a concept may be logically possible and yet cognitively empty, if it is impossible to conceive what it would be like to experience such a being. This latter point is important because, according to the Ontological Argument, if we can possibly conceive of an absolutely necessary being (God), then God must necessarily exist. Why? Because it would supposedly be contradictory to deny the existence of a being whose existence is absolutely necessary. If it is possible for the most real being to exist, then it must necessarily exist, because existence is part of [what] it means to be...

Here's more from Auburn University philosopher Roderick T. Long ( Reason and Value: Aristotle versus Rand ) on coherentism and reflective equilibration . The point of all this is to show that we can rationally construct reality-based systems of belief that do not require infallibility. Aristotle thus appears to be counseling two steps. First, pursue a coherentist strategy for discovering first principles, by provisionally accepting all the beliefs that initially seem true or plausible to us (including, but not limited to, our perceptual beliefs) as defeasibly justified, and then try to see which candidates for first principles best cohere with our total set of beliefs in wide reflective equilibrium. Second, once the first principles have been thus identified, pursue a foundationalist strategy for demonstrating and thus explaining the truth of our initial beliefs (or some of them) by deriving them from these first principles. The things well-known to us are genuinely known but not ...