I've been reading more philosophy lately and one consistent theme I've noticed is that philosophy is always looking for first principles or, put different, ways of avoiding infinite regress. What I mean by first principles is everything we know, believe, or follow can be challenged by looking for its basis, and when that is finished, we can repeat the challenge again by asking the same questions about the basis' basis. So we have to find a starting point that is either unchallengeable or can adequately respond to that challenge. I'm sure there are literally hundreds of examples, but I'm going to give four.
1) The First Cause of the Universe
This one is very popular among JBlog readers and has been attacked, defended, and then attacked again over the last few years. There are a number of permutations (St. Thomas Aquinas had a number of versions himself), but put simply the argument goes like this: everything we know is contingent in the sense that it exists as a result of something other than itself. But if these objects are contingent, then how could they exist? They must be contingent on other contingent objects, which are contingent on other contingent objects, etc. Basically all contingent objects depend on other contingent objects and that chain is infinitely long.
Religious philosophers try to avoid giving this answer by positing the existence of a non-contingent entity which necessarily exists. That entity is not contingent on anything else and can exist on its own. It necessarily exists. This is the First Cause, which is G-d.
2) The Foundations of Empirical Knowledge
Epistemology is the field of philosophy that deals with what we know, as well as what we can know. It creates conditions, both necessary and sufficient, for what constitutes knowledge. Put basically, knowledge is justified belief that is true. But what makes a belief justified?
There are a number of answers to this question (and some do away with the whole idea of justification entirely), but any theory of justification is going to require that the belief build on another belief. So belief A is justified by belief B. But how is belief B justified? By belief C. So it appears we have another example of an infinite regress, because each belief will be justified by some earlier belief.
Most of the epistemologists who consider justification a necessary condition fall into two categories: Coherentists and Foundationalists. The former believe that all our beliefs can be sustained by appealing to other beliefs we have in the system. This argument is essentially circular but not in a bad way. Each belief appeals to another belief as a basis of its justification and all the beliefs in the system are justified by other beliefs in the system. Foundationalists, however, argue that there are basic beliefs, which are beliefs that are capable of justification, but do not need to be justified themselves by other beliefs. This argument posits the existence of beliefs that are justified solely by experience and do not appeal to any other beliefs. By accepting the idea of a basic belief, they avoid the infinite regress problem.
3) The Origin of Law's Authority
Jurisprudence or legal theory deal with the important question of what gives law authority. If the law’s claim to authority is dependant on the law itself, then the law’s claim is circular. A law cannot be binding merely because it says that it is. Clearly some external source must be the basis of the law’s authority. But what is the basis of that law’s authority? Unless there is a source of law outside of law itself, law is relegated to infinite regress.
To make the question more concrete, here is an illustration. Take any statute passed by the U.S. Congress. Congress is authorized to make legislative enactments under Article I of the Federal Constitution, so Congress seems to be the source of the statute’s authority. But what is basis of Congress' authority? The Constitution. But what is the Constitution’s claim to authority? While Article VI of the Constitution deems it the supreme law of the land, a law cannot grant authority to itself. So we are back to square one: what is the source of Congress’ law-making power?
For the past few centuries this question was answered by two different camps. The Naturalists believed that G-d created natural norms, which vest man with the ability to create laws. G-d designed law-creating norms, and those norms could be used to create further, man-made laws, providing the laws conform with the original norms. These norms are also the primary sources of morality and therefore there must be some connection between the laws and morality.
The Legal Positivists answer this question by assuming that law's authority can be justified independent of other laws. John Austin argued that the original basis of law is the command of a sovereign who answers to no other and has the power to enforce his decrees. H.L.A Hart disagreed with Austin and argued that every legal system has a Rule of Recognition that is accepted voluntarily by some segments of the population. That acceptance generates a secondary rule, which is the basis of the primary rules, such as laws. So laws derive their authority from the voluntary acceptance of a class of society. The Rule of Recognition avoids the infinite regress problem.
4) The Source of Moral Obligations
This is an issue I haven't seen mentioned in anything I've read, but I probably haven't read enough of the literature. In two earlier posts (I, II) I questioned the reason why we are bound by Divine command. We are not normatively bound by a rule simply because someone, even G-d, proposed that rule. So if we are bound by G-d's command, it must be because there is some other moral obligation. But what is the source of that moral obligation? Any answer will just lead to the question of that obligation's source. I don't know the answer to this infinite regress problem.
I think it's an important question because if we can't figure out the basis for our normative obligations, why are we bound by G-d's will at all? And if we're not, what justification do we have to punish others who do not wish to voluntarily submit to G-d's will? For example, how can a Beis Din punish an Apikoris or order the destruction of Buddhist temple? Perhaps we can make a pragmatic argument, that allowing sinners to remain unpunished in our society negatively affects believers, so Beis Din's actions are not punishment as much as protecting our society. This argument lacks a normative foundation, so while it could serve as a justification, it is weak.