Three Forms of Evidence

An argument uses premises to reach a conclusion, but we can’t just accept that every valid argument proves the conclusion to be true. If an argument has a valid form, we need to know that the premises are true before we can know the conclusion is true. We rarely know for certain that the premises of an argument are true. Instead, we do our best at justifying the premises. One way to do this is to provide evidence—reasons we should believe something to be likely true or accurate. Many people equate “evidence” with “observation,” but there could be other reasons to accept beliefs as well. I will discuss three types of evidence:

Common Sense Assumptions vs. Self Evidence

I would like to know whether or not knowledge is possible, and whether or not it’s possible for a belief to be justified without observation. If observation is the only good reason to have a belief, then it’s not clear that we can have knowledge concerning mathematics, morality, or logic—and it might even be impossible to have knowledge about anything. Perhaps we can have good reasons to believe something based on common sense assumptions or self-evidence rather than observation. I will argue that that some beliefs are justified as “common sense assumptions” that are not self-evident, and they aren’t justified through observation. These assumptions are justified by embodying various intellectual virtues better than alternatives.

Review of Robert Audi’s The Good in the Right

Robert Audi’s The Good in the Right (2004) attempts to offer a comprehensive understanding of morality that incorporates W. D. Ross’s moral intuitionism, Kant’s categorical imperative, and intrinsic valus. I will summarize Audi’s major claims and assess their plausibility. The moral realist view that morality is irreducible to non-moral properties is traditionally the “intuitionist” project, and “intuitionism” is traditionally based on the idea that we know moral facts from “intuition”—and “intuition” is traditionally viewed as a realization that something is true based on self-evidence.¹ First, Audi argues that Ross’s intuitionism is “intuitive” and can help us determine our “prima facie duties.” He defends a moderate form of intuition and argues that many arguments against self-evidence are based on misunderstandings. Second, he argues that the categorical imperative can be used as a way to ground intuitionism and help us choose between conflicting duties. Third, he argues that an understanding of intrinsic value can be used as a way to further ground our duties.

Objections to Moral Realism Part 2: Intuition is Unreliable

Many ethicists agree that moral philosophy requires the use of intuition. My argument for moral realism itself requires the use of intuition. However, philosophers will require that we justify our use of intuition. Some philosophers have argued that intuition is too mysterious or unreliable to be used for philosophy. I will present the case that intuition represents our tendency to be unable to verbalize various justifications. I will explain how our intuitions makes use of relatively reliable justifications, consider four objections against intuition, and I will attempt to explain why the objections are not convincing.