Truth and the Parmenidean Postulate

A translation of the 5th fragment of the writings of the 6th century BC Greek philosopher Parmenides reads “For it is the same thing that can be thought as can be.” I interpret this fragment as telling us that the structure of thought is the structure of reality. It is the Parmenidean postulate. It reassures us that our thinking can lead us to the truth. The truth is what there is as it is apart from our thinking. Accurate expression of our thoughts are the true statements.

I include posts on truth as reminders amongst my blog posts on my stance towards our ability to get the truth and express it well. In the so-called Blogsphere there are posts accusing some, especially those with views which could be classified as left of center as denying truth or dismissing our ability to get it. It is uninteresting to accuse someone of denying that there is truth and then dismiss them as inconsistently asserting that it is true that nothing is true. It is interesting and helpful for understanding our own stance toward truth to figure out how there could be stances which in some consistent way hold that there is no truth. This post then develop previous posts on truth:Pope Francis’ nominalism and Truth skepticism

Here I want to connect acceptance of truth with theories of universals and the Parmenidean postulate. Theories of universals are outlined in the post on Pope Francis’ nominalism.

Realists accept the Parmenidean postulate. The structure of thought has universal terms and then so does reality apart from thought. Realists about universals are realists about truth. I conjecture that most accusations that someone is not a realist about truth are based on thinking their opponent is not a realist about universals. Their opponents refuse to be pinned down to giving exact definitions.

Conceptualist do not hold the Parmenidean postulate. We place a weaker demand –postulate-on our reason. We postulate that thought is suitable for leading humans to think of reliable ways of operating in reality. We concede that reality may have a different structure than our thinking. But we do not concede that there is no truth. True thoughts are those on reliable ways to operate in reality. Conceptualist set aside the task of trying to uncover the structure of reality apart from thought. That would be metaphysics.

Nominalist do not hold the Parmenidean postulate. Nominalists have a metaphysical theory on the structure of reality apart from thought. They hold that reality is simply many separate things. All talk of their interconnection distorts their separateness. But thinking is always about interconnections. Hence, nominalists do not accept any thoughts as true. By simply stating their metaphysical view without asserting it as true nominalists can consistently present their view. True is a necessarily empty category for noninalists.

So, if someone wants to make a philosophically strong case that someone else rejects truth, they should struggle to make a case their opponent is a nominalist. If someone wants to take the stance that there is truth which is properly expressed by our thoughts they should accept and defend the Parmenidean postulate.

I have written a book defending traditional sexual morality as a conceptualist. Thus I think daily practice will show the truth of traditional sexuality morality.
My book Confronting Sexual Nihilism: Traditional Sexual Morality as an Antidote to Nihilism was released by Tate Publishing on March 11, 2014. See Book Web Page for information about the book. The publisher’s listed price is $26.99. Printed copies can be purchased here by credit card for $3.99, plus $3.71 for shipping and handling.

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