I have to admit I fall into the camp that tends to dismiss 1960s French philosophy as a postmodernist dead end. Not because I'm hysterical about it, but because I haven't been convinced of its intellectual worth. I say this as somebody who isn't afraid to engage deeply with obscure thinkers when necessary. So I would be genuinely interested to hear what it is you think made that time so creative, and I guess the second question is how you think about the balance "creativity" in philosophy against other desiderata such as having good arguments and evidence for your theories.

I'm not as familiar with academic philosophy from the last 25 years, but if you look at the late 20th century, there are lots of examples of very creative philosophical work. Here are some thinkers who I personally think are extremely creative philosophers.

Graham Priest – He is known for defending dialetheism, which is the view that contradictions can be true. But more importantly, in numerous books, he uses his logical views to defend a huge variety of very interesting new philosophical theories to explain everything from intentionality to mereology in a framework of paraconsistent logic.

Charles Taylor – Canadian philosopher who did very creative work about the rise of authenticity as a core moral value in the West.

Edward Zalta – Another logician, who puts forward an extraordinarily novel and interesting logical framework for solving the longstanding Fregean problems in philosophy of language by proposing a split in the meaning of the word "is."

Derek Parfit – I saved the best for last. In my view, one of the most creative philosophers ever. He raised the level of discussion of the metaphysical and moral questions surrounding personal identity into an entirely new intellectual register. Reasons and Persons is like a smorgasbord of creative new ideas.

As others posters have mentioned, there are other philosophers from earlier in the 20th century or late 19th century who are very creative and have not yet been entirely digested by even the academic philosophical community, let alone by the general public.

My personal favorite is Maurice Merleau-Ponty. I think a lot about how different the intellectual history of continental philosophy might have been if he hadn't died young before completing his third major book. Many people missed the fact that Merleau-Ponty isn't just a philosopher of the body or perception, but rather a truly general philosopher who gives innovative answers to classic philosophical questions by attempting to ground philosophy in pre-reflective perception.

Philosophers that people have told me are extremely creative but whom I have not personally had a chance to read are Alfred North Whitehead, Charles Peirce, and Henri Bergson. I do think that something happened around the beginning of the 20th century, roughly the 1920s, possibly as a result of disillusionment from World War I, possibly because we hit a cognitive bottleneck. But it does seem that even though creative new philosophical ideas were still being invented, the academic and wider social community stopped digesting them. This, in turn, may have led most academic philosophers to stop trying to create "big theories" and focus instead on micro-analysis. After all, what's the point of putting forward a big new theory if so few people are going to read or understand it?

 

A god that is beyond comprehension, beyond knowing, beyond words or thought is also beyond worship except for philosophers and mystics, a very distinct minority.

In the quote I gave from Tillich he doesn't say anything about God being beyond comprehension or beyond knowing. And if you read the larger context of that quote in the book, you won't find much of that type of apophatic theology. I'm not saying he doesn't make gestures in that direction, but I guess I'm trying to say that there is a more concrete and experientially grounded side to Tillich's philosophy.

In other words, there is a positive phenomenology to the experience of the divine, as well as the demonic within the larger phenomenology of the Holy. There is a stark philosophical difference between this perspective, which we might call a theology of the numinous, and the apophatic theology which says God is fundamentally beyond any direct experience or intellectual understanding.

When it comes to worship, by grounding theology in the Holy, there is also a basis for understanding worship and ritual as outward or material expression of the experience of the Holy. In the same way that a physical painting is an outer expression of the artist's aesthetic vision or sensibility or style, the religious worship service is a outer expression of historical encounter with the divine in the the Holy. It may be true that the average participant in the religion doesn't have an intense direct experience on par with the mystic or the prophet, but they can still participate in the sacred encounter indirectly via the outer ritual and worship practices.

I'd like to try to ground this discussion by looking at what Tillich and others actually say about God, rather than oversimplifying their views as saying that God is being itself.

One of my favorite books by Tillich is Dynamics of Faith which is a really good read and not too long, he writes:

"The mysterious character of the holy produces an ambiguity in man’s ways of experiencing it. The holy can appear as creative and as destructive...One can call this ambiguity divine-demonic, whereby the divine is characterized by the victory of the creative over the destructive possibility of the holy, and the demonic is characterized by the victory of the destructive over the creative possibility of the holy."

A couple of crucial things here that make the picture a bit more complex than saying God is just being itself. First of all, Tillich is situating the divine / God within a broader category that he calls "the Holy". He is drawing here on ideas from the book, The Idea of the Holy, by Rudolf Otto. The category of the Holy, might in our contemporary language be better translated as "sacredness" or "numinosity". We could think of it as a phenomenological dimension of Transcendence-Immanence.

What I like about the passage above is Tillich's insistence that The Holy does not only contain what we think of as God or the divine, but also what we think of as the demonic or supermundane Evil. Religious faith, in Tillich's view, is not so much a belief in some specific story about God, such as the Bible or the Bhagavad Gita but rather the common attitude that is found in all such sacred narratives about the divine. Namely, that despite the dual divine-demonic nature of the dimension of Transcendence-Imminence, there is nevertheless a deeper truth, or ultimate metaphysical priority in the positive life-affirming side of this duality.

This conception of religious faith, gives us a philosophy of religion, and a philosophy of the nature of God, that is more attuned to the experiences of mystics and prophets, rather than the belief systems of the average religious person. We should remember that almost all religions claim to be based in the revelations provided by God to some mystic or prophet. So even if the attitude towards God and faith that Tillich is describing is one shared by a comparative minority of religious believers, it is nevertheless at the root of the nature of religion itself. So I think from a philosophical point of view it is crucial to try to understand this.

what is an "infinite steaming interaction"?

In computer science an infinite stream is a data structure where you can pull off the front part of an infinite series. For example, you can have the list of all the Fibonacci numbers as an infinite stream. Of course, you can't actually store infinite values in memory, but effectively it means that as you ask for values initial segment of the stream those values are computed on the fly and you receive a new stream which is shifted.

So e.g., if you start with the infinite stream [1, 1, 2, 3, 5, 8, 13, 21,... ]

Then you take the first three, you deconstruct your original stream to get a finite list [1,1,2] and a new infinite stream [3, 5, 8, 13, 21,... ] which is a shifted version of the original.

Now applying this to real numbers. We can represent a real number in the open unit interval as an infinite stream of natural numbers (so we don't have to worry about where the decimal point lies). If we take the head (first value) and tail (a new stream shifted over by 1), the new stream is also a real number. So this is what I meant by "an infinite streaming interaction". This operation arises naturally as the final coalgebra of the ordinal product functor in the category of partially ordered sets. And the carrier set of this coalgebra is order isomorphic to the reals (i.e., it is equivalent as a partially ordered set).

This topic makes me think about how for a long time analytic philosophy regarded language as the stuff out of which concepts are made. I was listening recently to this podcast interview with the neuroscientist Ev Fedorenko. She makes a remarkably strong empirical argument that conceptual representations in the brain are language independent. According t her work, language is more like a system of pointers to non-linguistic multi-modal representations. This turns so much of 20th century analytic philosophy on it head (goodbye later Wittgenstein, goodbye Dummett). I don't know if any contemporary philosophers in the analytic tradition have attempted to grapple with this.

There is a nice mathematical way to cash our the intuition the original poster is gesturing towards. See The continuum as a final coalgebra shows that the real numbers (a.k.a. the continuum) can be constructed from infinite steaming interactions over infinite sequences of natural numbers. I like this definition because it gives a more operational sense of how to think of the reals as being generated out of the naturals.