I have worked in philosophy for over sixty years and implicitly never regarded philosophical claims as genuinely true, if true at all.
I started graduate study of philosophy in 1958 at the University of Minnesota. Logical positivism was the dominant philosophy. Herbert Feigl an Austrian refugee who had been a member of the Vienna Circle directed its Philosophy of Science Center. I had written an undergraduate honors thesis on Hume and the self. I was very upset with Humean skepticism; especially with philosophy’s apparent inability to say what made me who I am. I did not follow Hume’s recommendation to stop gloomy philosophical reflections and just go about the business of living. Perhaps, I hoped that I could find some solid results in deeper study of philosophy. I received a Ph. D. in Philosophy and Mathematics in 1962. At the end of graduate study, I could not answer the question: What philosophical truths did you learn in graduate study and Ph.D. research? I cannot say that I taught students any philosophical truths during forty years of teaching. What I wrote for journals was mostly criticism of what others had written. I published many truths about logic in a book on entailment systems. But those were mathematical truths.
I owe much to my instructors and the texts of classical philosophy for teaching me how to philosophize. However, I could not figure out how this disciplined thinking could lead to discovery of any truth. Early in graduate study, I read Wittgenstein’s Tractatus. In the Tractatus, I met the only forthright philosophical truth claims I ever encountered. The Tractatus gave a bold statement of the metaphysics of logical positivism. I now reject a crucial truth claim of that metaphysics, viz., logical atomism. Atomism led to Naturalism. By implicitly hold atomism all of these years, I implicitly accepted the metaphysics that in fact there was and could be nothing but what provided truth conditions for the truth claims of natural sciences.
I sketch a diagnose why I gave up hope of there being genuine philosophical truth claims. Next, I point how I have now revived a belief that there can be genuine philosophical truth claims. I base my sketch on correcting the metaphysics of the Tractatuss.
A genuine truth claim is one that represents what exists as having certain features. If what exists has those features it is true. If what exists does not have those features it is false. The features attributed to what exists do not provide a picture of what exists. We cannot even think of what exists apart from features we attribute to it; let alone imagine it. Realism is holding that there are genuine truth claims. For positivism a genuine truth claim was cognitively meaningful.
Logical positivism, especially as expressed in the Tractatus, and the criticism of it have left a long legacy.
Here are core assumptions of logical positivism and results of he criticism of it which the Tractatus incorporated into positivism.
1. Realism: There are genuine truth claims
2. Atomism: Truth conditions are constituted by some basic elements whose existence or non-existence is independent of anything else.
3. The only necessity is logical necessity
4. A claim that realism and atomism are true is not a genuine truth claim. This comes from positivism’s self criticism.
I think Wittgenstein himself gave up realism because he came to think that there were non-logical necessities such as “No surface is uniformly red and green.” Non-logical necessities threatened atomism because there, then, might be connections which threaten the independence of the basic elements. He probably thought that there could not be truth conditions without independent existents.
I reject atomism because it is a claim about what truth conditions are like apart from our representation of them. Also atomism clashes with a thesis that the only necessity is logical necessity. It rules out the logical possibility of the interconnection of every existent. I accept realism as a philosophical truth claim. If nothing exists to make claims true, realism is false; otherwise it is true. Of course I cannot stand back an look at exists apart from my representing to verify that the claim of realism is true. So, I am content to class it as an ASSUMPTION OF A TRUTH.
The dismissal of atomism is a tremendous philosophical assumption. Atomism brings with it naturalism. For if anyone can think of elements whose order and connection provide truth conditions for natural physical science, those elements do not even provide truth conditions for claims about the mental; let alone religion.
It must be emphasized that setting aside atomism is not a accepting monism. i.e. what exists is a unity. There is no claim about what exists as a thing or things in themselves.
So, I close this post by finally proclaiming a philosophical truth. That philosophical truth is what I offered in my previous post. There is a vast diversity of genuine truth claims.