Abraham Joshua Heschel basically takes the ineffable, and our experience of the ineffable, as an axiom in his philosophy of religion. The experience of the ineffable is something not too far from Polyani’s tacit knowledge – it is experience that we cannot codify or put into words but remains no less real for that fact.
Another key axiom for Heschel is ‘wonder’. This actually plays a key role in his epistemology:
‘Standing eye to eye with being as being, we realize that we are able to look at the world with two faculties – with reason and with wonder. Through the first we try to explain or adapt to world to our concepts, through the second we seek to adapt our minds to the world.’ (‘Man is Not Alone’, p. 11)
So wonder is a kind of epistemic reaction to the reality of being, if that makes sense. What the classical tradition called the ‘active intellect’ is Heschel’s ‘reason’ – how we organize, categorize, conceptualize and formalize the world:
‘Wonder is a state of mind in which we do not look at reality through the latticework of our memorized knowledge; in which nothing is taken for granted.’ (p. 12)
Wonder can then be defined here as the immediate, tacit apprehension of being as such – the sheer there-ness of the world. Not this or that particular reality, at least in this case:
‘Radical amazement has a wider scope than any other act of man. While any act of perception or cognition has as its object a selected segment of reality, radical amazement refers to all of reality; not only to what we see, but also to the very act of seeing as well as to our own selves, to the selves that see and are amazed to see.’ (p. 13)
Heschel defines radical amazement as what happens when we are struck with wonder – radical amazement is what follows immediately after wonder. It’s the wordless pre-conception, precognition state of mind that lies beneath all inquiry of any kind.
An interesting aspect of Heschel’s epistemology is the tacit component. Heschel rejects out of hand the notion that there is nothing in the intellect that was not first in the senses – he does the same for a priori reasoning as well. This he calls ‘insight’:
‘Just as the mind is able to form conceptions supported by sense perception, it can derive insights from the dimension of the ineffable. Insights are the roots of art, philosophy and religion, and must be acknowledged as common and fundamental facts of mental life.’ (p. 17)
The insight is a primordial datum, so to speak – it’s what our mind apprehends in its state of wonder when it comes into contact with being as being – which is beyond the realm of logical codification. This is where Heschel comes very close to Polyani – this aspect of the mental life is fundamental for both of them. That there are things we can know but only grasp tacitly, wordlessly is an axiom for both. Insights are beyond logic and beyond expression and beyond sensory perception – an insight is, perhaps, what being tells us when we apprehend it.