Question: When was the death of the person that was a friend and former student that Whitehead discussed the goals of science with?

full_context: Document 1: Empiricism: The phenomenalist phase of post-Humean empiricism ended by the 1940s, for by that time it had become obvious that statements about physical things could not be translated into statements about actual and possible sense data. If a physical object statement is to be translatable into a sense-data statement, the former must be at least deducible from the latter. But it came to be realized that there is no finite set of statements about actual and possible sense-data from which we can deduce even a single physical-object statement. Remember that the translating or paraphrasing statement must be couched in terms of normal observers in normal conditions of observation. There is, however, no finite set of statements that are couched in purely sensory terms and can express the satisfaction of the condition of the presence of a normal observer. According to phenomenalism, to say that a normal observer is present is to make the hypothetical statement that were a doctor to inspect the observer, the observer would appear to the doctor to be normal. But, of course, the doctor himself must be a normal observer. If we are to specify this doctor's normality in sensory terms, we must make reference to a second doctor who, when inspecting the sense organs of the first doctor, would himself have to have the sense data a normal observer has when inspecting the sense organs of a subject who is a normal observer. And if we are to specify in sensory terms that the second doctor is a normal observer, we must refer to a third doctor, and so on (also see the third man).
Document 2: Karl Popper: As early as 1934, Popper wrote of the search for truth as "one of the strongest motives for scientific discovery." Still, he describes in Objective Knowledge (1972) early concerns about the much-criticised notion of truth as correspondence. Then came the semantic theory of truth formulated by the logician Alfred Tarski and published in 1933. Popper writes of learning in 1935 of the consequences of Tarski's theory, to his intense joy. The theory met critical objections to truth as correspondence and thereby rehabilitated it. The theory also seemed, in Popper's eyes, to support metaphysical realism and the regulative idea of a search for truth.
Document 3: Philosophiæ Naturalis Principia Mathematica: The French mathematical physicist Alexis Clairaut assessed it in 1747: "The famous book of Mathematical Principles of Natural Philosophy marked the epoch of a great revolution in physics. The method followed by its illustrious author Sir Newton ... spread the light of mathematics on a science which up to then had remained in the darkness of conjectures and hypotheses."A more recent assessment has been that while acceptance of Newton's theories was not immediate, by the end of a century after publication in 1687, "no one could deny that" (out of the Principia) "a science had emerged that, at least in certain respects, so far exceeded anything that had ever gone before that it stood alone as the ultimate exemplar of science generally."In formulating his physical theories, Newton developed and used mathematical methods now included in the field of calculus. But the language of calculus as we know it was largely absent from the Principia; Newton gave many of his proofs in a geometric form of infinitesimal calculus, based on limits of ratios of vanishing small geometric quantities. In a revised conclusion to the Principia (see General Scholium), Newton used his expression that became famous, Hypotheses non fingo ("I feign no hypotheses").
Document 4: Alfred North Whitehead: This is not to say that Whitehead's thought was widely accepted or even well-understood. His philosophical work is generally considered to be among the most difficult to understand in all of the western canon. Even professional philosophers struggled to follow Whitehead's writings. One famous story illustrating the level of difficulty of Whitehead's philosophy centers around the delivery of Whitehead's Gifford lectures in 1927–28 – following Arthur Eddington's lectures of the year previous – which Whitehead would later publish as Process and Reality:
Document 5: Alfred North Whitehead: Deleuze's and Latour's opinions, however, are minority ones, as Whitehead has not been recognized as particularly influential within the most dominant philosophical schools. It is impossible to say exactly why Whitehead's influence has not been more widespread, but it may be partly due to his metaphysical ideas seeming somewhat counter-intuitive (such as his assertion that matter is an abstraction), or his inclusion of theistic elements in his philosophy, or the perception of metaphysics itself as passé, or simply the sheer difficulty and density of his prose.
Document 6: Alfred North Whitehead: Early followers of Whitehead were found primarily at the University of Chicago's Divinity School, where Henry Nelson Wieman initiated an interest in Whitehead's work that would last for about thirty years. Professors such as Wieman, Charles Hartshorne, Bernard Loomer, Bernard Meland, and Daniel Day Williams made Whitehead's philosophy arguably the most important intellectual thread running through the Divinity School. They taught generations of Whitehead scholars, the most notable of which is John B. Cobb, Jr.
Document 7: Idealism: Bradley was the apparent target of G. E. Moore's radical rejection of idealism. Moore claimed that Bradley did not understand the statement that something is real. We know for certain, through common sense and prephilosophical beliefs, that some things are real, whether they are objects of thought or not, according to Moore. The 1903 article The Refutation of Idealism is one of the first demonstrations of Moore's commitment to analysis. He examines each of the three terms in the Berkeleian aphorism esse est percipi, "to be is to be perceived", finding that it must mean that the object and the subject are necessarily connected so that "yellow" and "the sensation of yellow" are identical - "to be yellow" is "to be experienced as yellow". But it also seems there is a difference between "yellow" and "the sensation of yellow" and "that esse is held to be percipi, solely because what is experienced is held to be identical with the experience of it". Though far from a complete refutation, this was the first strong statement by analytic philosophy against its idealist predecessors, or at any rate against the type of idealism represented by Berkeley. This argument did not show that the GEM (in post–Stove vernacular, see below) is logically invalid.
Document 8: Empiricism: The neopositivists subscribed to a notion of philosophy as the conceptual clarification of the methods, insights and discoveries of the sciences. They saw in the logical symbolism elaborated by Frege (1848–1925) and Bertrand Russell (1872–1970) a powerful instrument that could rationally reconstruct all scientific discourse into an ideal, logically perfect, language that would be free of the ambiguities and deformations of natural language. This gave rise to what they saw as metaphysical pseudoproblems and other conceptual confusions. By combining Frege's thesis that all mathematical truths are logical with the early Wittgenstein's idea that all logical truths are mere linguistic tautologies, they arrived at a twofold classification of all propositions: the analytic (a priori) and the synthetic (a posteriori). On this basis, they formulated a strong principle of demarcation between sentences that have sense and those that do not: the so-called verification principle. Any sentence that is not purely logical, or is unverifiable is devoid of meaning. As a result, most metaphysical, ethical, aesthetic and other traditional philosophical problems came to be considered pseudoproblems.
Document 9: Context principle: The context principle is one of Gottlob Frege's ``three fundamental principles ''for philosophical analysis, first discussed in his Introduction to The Foundations of Arithmetic (Grundlagen der Arithmetik, 1884). Frege argued that many philosophical errors, especially those related to psychologism in the philosophy of logic and philosophy of mathematics, could be avoided by adhering carefully to the context principle. The view of meaning expressed by the context principle is sometimes called contextualism, but should not be confused with the common contemporary use of the term contextualism in epistemology or ethics. This view need not be contrasted with the view that the meanings of words or expressions can (or must) be determined prior to, and independently of, the meanings of the propositions in which they occur, which is often referred to as compositionalism.
Document 10: Alfred North Whitehead: The two volume biography of Whitehead by Victor Lowe is the most definitive presentation of the life of Whitehead. However, many details of Whitehead's life remain obscure because he left no Nachlass; his family carried out his instructions that all of his papers be destroyed after his death. Additionally, Whitehead was known for his "almost fanatical belief in the right to privacy", and for writing very few personal letters of the kind that would help to gain insight on his life. This led to Lowe himself remarking on the first page of Whitehead's biography, "No professional biographer in his right mind would touch him."
Document 11: Introduction to Mathematical Philosophy: Introduction to Mathematical Philosophy is a book by Bertrand Russell, published in 1919, written in part to exposit in a less technical way the main ideas of his and Whitehead's "Principia Mathematica" (1910–13), including the theory of descriptions.
Document 12: Alfred North Whitehead: Isabelle Stengers wrote that "Whiteheadians are recruited among both philosophers and theologians, and the palette has been enriched by practitioners from the most diverse horizons, from ecology to feminism, practices that unite political struggle and spirituality with the sciences of education." Indeed, in recent decades attention to Whitehead's work has become more widespread, with interest extending to intellectuals in Europe and China, and coming from such diverse fields as ecology, physics, biology, education, economics, and psychology. One of the first theologians to attempt to interact with Whitehead's thought was the future Archbishop of Canterbury, William Temple. In Temple's Gifford Lectures of 1932-1934 (subsequently published as "Nature, Man and God"), Whitehead is one of a number of philosophers of the emergent evolution approach Temple interacts with. However, it was not until the 1970s and 1980s that Whitehead's thought drew much attention outside of a small group of philosophers and theologians, primarily Americans, and even today he is not considered especially influential outside of relatively specialized circles.
Document 13: Idealism: and proliferation of hyphenated entities such as "thing-in-itself" (Immanuel Kant), "things-as-interacted-by-us" (Arthur Fine), "table-of-commonsense" and "table-of-physics" (Sir Arthur Eddington) which are "warning signs" for conceptual idealism according to Musgrave because they allegedly do not exist but only highlight the numerous ways in which people come to know the world. This argument does not take into account the issues pertaining to hermeneutics, especially at the backdrop of analytic philosophy. Musgrave criticized Richard Rorty and Postmodernist philosophy in general for confusion of use and mention.
Document 14: Alfred North Whitehead: Whitehead did not begin his career as a philosopher. In fact, he never had any formal training in philosophy beyond his undergraduate education. Early in his life he showed great interest in and respect for philosophy and metaphysics, but it is evident that he considered himself a rank amateur. In one letter to his friend and former student Bertrand Russell, after discussing whether science aimed to be explanatory or merely descriptive, he wrote: "This further question lands us in the ocean of metaphysic, onto which my profound ignorance of that science forbids me to enter." Ironically, in later life Whitehead would become one of the 20th century's foremost metaphysicians.
Document 15: Alfred North Whitehead: Rather than teach small parts of a large number of subjects, Whitehead advocated teaching a relatively few important concepts that the student could organically link to many different areas of knowledge, discovering their application in actual life. For Whitehead, education should be the exact opposite of the multidisciplinary, value-free school model – it should be transdisciplinary, and laden with values and general principles that provide students with a bedrock of wisdom and help them to make connections between areas of knowledge that are usually regarded as separate.
ground_truth: 1970
sub_queries: With what friend and former student did Whitehead correspond regarding the goals of science? Answer: Bertrand Russell
When did Bertrand Russell die? Answer: 1970