In the introduction to his 900-page opus, The History of Western Philosophy, he writes:
“Philosophy, as I shall understand the word, is something intermediate between theology and science. Like theology, it consists of speculations on matters as to which definite knowledge has, so far, been unascertainable; but like science, it appeals to human reason rather than to authority, whether that of tradition or that of revelation. All definite knowledge--so I should contend-- belongs to science; all dogma as to what surpasses definite knowledge belongs to theology. But between theology and science there is a No Man's Land, exposed to attack from both sides; this No Man's Land is philosophy.”
Despite his assertion that philosophy is a no man’s land, Russell insists that human beings must depend on philosophy for finding some kind of answers to all the questions about the nature of existence. Here’s the list questions for which he expects philosophy to provide the answers:
“Is the world divided into mind and matter, and, if so, what is mind and what is matter? Is mind subject to matter, or is it possessed of independent powers? Has the universe any unity or purpose? Is it evolving towards some goal? Are there really laws of nature, or do we believe in them only because of our innate love of order? Is man what he seems to the astronomer, a tiny lump of impure carbon and water impotently crawling on a small and unimportant planet? Or is he what he appears to Hamlet? Is he perhaps both at once? Is there a way of living that is noble and another that is base, or are all ways of living merely futile? If there is a way of living that is noble, in what does it consist, and how shall we achieve it? Must the good be eternal in order to deserve to be valued, or is it worth seeking even if the universe is inexorably moving towards death? Is there such a thing as wisdom, or is what seems such merely the ultimate refinement of folly?”
Russell claims that we have to depend on philosophy for answers to “almost all the questions of most interest to speculative minds” because we have no other alternative for gaining knowledge, given that science and theology are incapable of taking us to the truth.
The answers, he says, cannot be found in a laboratory. He rejects science, or the idea of gaining knowledge through the study of objects and processes, as a source of philosophical knowledge because he thinks that complete knowledge is beyond the grasp of human beings.
“Science tells us what we can know, but what we can know is little, and if we forget how much we cannot know we become insensitive to many things of very great importance.”
He rejects theology as a source of knowledge because he seems to think that the knowledge that we get through theology is “all too definite,” and “their very definiteness causes modern minds to view them with suspicion.”
“Theology, on the other hand, induces a dogmatic belief that we have knowledge where in fact we have ignorance, and by doing so generates a kind of impertinent insolence towards the universe.”
From all this we can infer the basic tenets of Russell’s bizarre theory of epistemology—he believed that science is the vehicle for indefinite knowledge, theology is the vehicle for definite knowledge, and philosophy is the no man’s land between indefinite-science and definite-theology. Surely, this does not make any sense.
He goes on to propose that human beings have no alternative except to endure uncertainty. Only the tolerance of uncertainty will enable us to live a life without the support of “comforting fairy tales.” But how can skepticism free us from fairy tales? Russell does not explain how he arrives at such illogical conclusions; he presents his ideas as arbitrary assertions.
“It is not good either to forget the questions that philosophy asks, or to persuade ourselves that we have found indubitable answers to them. To teach how to live without certainty, and yet without being paralyzed by hesitation, is perhaps the chief thing that philosophy, in our age, can still do for those who study it.”
Along with being a philosopher, Russell was also a mathematician. Apparently, he pursued mathematics by denying reality. They gave him the Nobel Prize in Literature 1950 "in recognition of his varied and significant writings in which he champions humanitarian ideals and freedom of thought.”