I have read that some Eastern philosophies, such as Buddhist philosophy, have considered extra-sensory perception (as attained through meditation), a valid source of knowledge. For example, the Buddha was described to have verified the law of karma through this extrasensory mode of perceiving.
Has there been any Western philosophy that accepts this as a valid source of knowledge? Or is this unique to Eastern thought?
ESP is not a widely recognised source of knowledge in the Western tradition - probably something of an understatement. It would be dogmatic to say that ESP does not occur or is impossible. Acceptance faces two main problems : (1) it does not have, or has not been perceived to have had, reliable practical applications; and (2) it has not been clearly demonstrated to occur under laboratory conditions.
None the less Professor H.H. Price of Oxford, and Professor C.D. Broad of Cambridge, were in the not too distant past sympathetically interested in ESP. Both were highly respected professional philosophers. Right-headed or wrong-headed on this issue, they do represent a slice of interest in ESP in Western philosophy.
Early Buddhism holds that there are six consciousnesses, 5 that occur in conjunction with the senses, and 1 'idea sense'. In the Yogacara philosophy which is taken up by most Mahayana school (Chinese+Tibetan), this was developed into https://en.m.wikipedia.org/wiki/Eight_Consciousnesses So, 'extra sensory' in the Buddhist context, is still perception, with the mind, in various ways, including verifying the law of karma. In modern framing we understand the Earth having a liquid magnetic core, cyanobacteria producing oxygen, and our own genetic lineages. When you look at the actual Buddhist account of karma which sets it in vast space and time (just 1 kalpa is around 3 x the current age of the universe), rather than tge popular idea which is like the Hindu description, it is quite comparable to that modern thinking.
There is an issue like with all pre-scientific theology, in distinguishing between metaphor and literalism, as we use those categories now. A strong case can be made for Buddha presenting thought experiments (parable of the arrow, the mother and the mustard seed), and reinterpreting ideas of his time to serve philosophical and ethical insights (karma, cosmology, conditionality); but presenting these in modern understanding as literally true. Voyaging into other realms sounds 'extra sensory', but again when you look at the actual texts https://www.accesstoinsight.org/lib/authors/jootla/wheel414.html it sounds more like theology, dealing with Brahma as 'causeless cause', and with dismissing appeals to external beings that distract us from our own psycology and choices.
'Extra sensory perception' is poorly defined in Western thought too. Are ideas, like infinity, 'extra sensory'? You have to say yes, but it's not what people jump to. Birds and cattle sense the Earth's magnetic field, and humans have the same type of cells they do it with. 'Extra-sensory'? Or just another sense? Modern reviews list us having 42 senses, from our stomachs acidity to proprioception. Any 'new' way of sensing that was demonstrated to actually work, would be added to the list. While, we 'voyage' into all kinds of othervrealms in modern physics, like mathematical phase spaces where we arrange information to identify manifolds or surfaces with specific properties, and draw out results of importance for 'ordinary space'. But even that latter, is fractal, almost certainly holographic, and far from our simple intuition of 'material' or even 'real'.
Plato's story of Er https://en.m.wikipedia.org/wiki/Myth_of_Er is remarkably like Buddhist thinking, such as in The Tibetan Book Of The Dead. I just don't accept the distinction between Eastern & Western thinking on ESP. Only, between ancient and modern, and even that mainly as an issue of terminology. In our modern thinking, ESP doesn't really make sense as a category, and we might draw inspiration in fact from descriptions of realms in Buddhist thought, as from maths and physics, in countering our intuitions and examining the actual nature of what is 'reality'.
In the Western tradition the only super-natural awareness that is treated sympathetically is that of revelation as in the revealed religions as in the prophetic tradition of Judaism, Christianity & Islam, and also Brahman in Hinduism and of non-duality in Buddhism.
However, these are definitely not ESP as commonly or popurlarly understood.
For the most part, the source of knowledge is not something that determines its validity. To attribute the validity to the source is the fallacy of appeal to authority.
Knowledge is generally separated from belief by 'justification'. Something stops being simply a belief and becomes knowledge if it integrates with other knowledge in a way that reinforces them both. To the degree this becomes firmer over time, belief derived from any source at all may become knowledge.
This is integrated into basic views of Western science (a la Popper, but basically in the whole tradition). In the process of hypothesis testing, we never say much about what hypotheses we should entertain, or where they are supposed to come from. What matters is that they integrate with the theory, and that to the degree they extend the theory those extentions could theoretically be tested.
