Philosophy of Science - Part II

Philosophy of Science – Part II

Einstein

Albert Einstein solved a central problem of science with his theory of special relativity and it was this that influenced philosophers of science to further understanding in the field. A principle of relativity refers to the idea that unaccelerated motion can be described only in respect to a specific frame of reference.

Einstein was associated with two specific principles that are germane to the present thread of philosophy of science: 1) the relativity of unaccelerated motion as well as 2) the non-relativity of the speed of light. Einstein re-examined the assumptions scientists made about space and time. Depending on their frame of reference two observers traveling relative to one another will have different opinions about when an event happened, or whether one event happened before another. Einstein asserted that the question “when did this event happen” is scientifically meaningless.

In a similar way, different observers in motion (as described above) will measure an object’s length differently. “All can be right provided we reject the notion that the object’s length is independent of the reference frame from which it is measured.” A lot of what Einstein accomplished hinged on his linking such concepts very tightly to experience and measurement, while he denied that they had “legitimate use when disconnected from experience and measurement.”

P.W. Bridgeman expanded upon the philosophical ramifications of Einstein’s innovations with operationalism, which entails defining each scientific concept solely in terms of the operations required to detect and/or measure specific instances of phenomena.

Classical Empiricism

To understand better the connections between experience and meaning that operationalism attempts to convey, we must examine the philosophical history of “reflection about experience, language, and belief.”  Locke, Berkeley, and Hume created a common tradition of empiricism—“the idea that experience sets the boundaries of, and provides the justification for, our claims to knowledge.” The classical empiricist began to reject the very notion of a useful metaphysics and to build knowledge upon the bedrock of that which can be observed by the senses and deduced by the intellect from these observations.

Broadly speaking, empiricism refers to the notion that all that we can know about the universe is only that which can be communicated by sensory input—observation of the external world. Locke wanted to determine the boundaries of our knowledge by investigating its sources. He asserted, “Nothing is in the mind that was not first in the senses.” Thus, for Locke, when the mind thinks, that is the substance of an idea. These ideas are mind-dependent. We perceive sights, sounds, textures, odors, etc. but we do not perceive actual objects. Also according to Locke, simple ideas come from experience and then our innate mental powers, such as pattern-recognition and abstraction, elaborate our simple ideas. “Abstraction lets us focus on a part of a presented idea… and these parts can be recombined to form ideas of things never presented in experience, such as unicorns.”

Despite his rejection of the label, many of Berkeley’s colleagues considered him a skeptic because he denied the existence of matter. Berkeley argued that we have no an idea of material substance. First, we have no direct experience of matter. We grasp to describe what matter alone might look or feel like. Second, Berkeley argued that it was impossible for us to construct a legitimate idea of matter based on our ability of abstraction. Without knowledge of a thing’s properties, how might we imagine it at all? Finally, Locke had admitted some confusion about how ideas are produced in us and according to Berkeley, “God simply produces ideas in us directly.” God does not need the intermediary of matter to produce in us ideas. According to Berkeley, our patterns of experience are the world itself. Science is reducible to the development of rules which predict our experiences.

Finally, David Hume demonstrated the devastating effects of this pure skepticism espoused within, if not by, Berkeley. Hume’s sought to bring experimentation to philosophy. However, this proved difficult because of the lack of “testable” hypotheses. According to Hume we have no inkling of causation, how one event might be observed to “make” another event happen. Experience simply shows us the correlation: the first thing happens, then the next. For us, their connections are not experiential. There is a lack of continuity as well. The only thing experience provides us with is that which is “currently perceived by us.”

This position as a starting point is deeply skeptical. Thus, Hume asserted that “all meaningful statements must concern either relations of ideas, as in logic and mathematics, or matters of fact, as in the empirical sciences. This influential dichotomy is known as Hume’s fork.” Hume thus felt that he was engaged in a kind of psychology, attempting to determine principles about the human mind in a manner like Newton had applied toward the cosmos. 

Logical Positivism and the Closely Related Logical Empiricism

Logical positivism and logical empiricism, together form neopositivism, a movement within Western philosophy that turned to verificationism, which tries to make philosophy a bit more like science. For example, under verificationism, statements that are verifiable either logically or empirically are the only ones considered cognitively meaningful. The Berlin Circle and the Vienna Circle propounded logical positivism starting in the late 1920s. It attempted to reduce confusion in language and method between philosophy and science.

The logical positivists were responsible for making philosophy of science a much more serious undertaking within the overall study of philosophy. Logical positivists were influenced by Einstein’s work and other physics developments but largely disregarded 20^th century German philosophy which was otherwise somewhat influential in other subfields.

Logical positivists were less worried than Popper had been about pseudoscience and focused more on metaphysics and philosophy’s potential for impeding progress in physics. Like Auguste Comte the logical positivists were largely disappointed with efforts at a metaphysics—this accounted for the positivist part of the name. The logical part of logical positivism concerns their belief that mathematical logic had tools which could give rise to a stronger version of empiricism and weaker version of metaphysics. “This new version of empiricism grasped the other option presented by Hume’s fork. For the positivists, the philosopher deals in relations of ideas, not matters of fact.” It is the job of philosophy to clarify linguistic problems and show signs of the relationships between scientific statements and experience.  

Basically, logical positivism holds that every cognitively meaningful statement falls into one of two categories:  1) analytic or, 2) a claim about experience. Cognitively meaningful statements are literally true or false. Thus commands and questions are not statements subject to this dichotomy. Analytic statements have to do with Hume’s relation of ideas. They are true or false based on their meaning and are not true or false statements. Thus, analytic statements are knowable a priori; empirical evidence is not required to know the truth of logical and mathematical propositions. Such analytic truths also hold necessarily. For example, “It is not merely true that no bachelor is married; it must be true.” It is true in all possible worlds. At this point, metaphysics is disregarded as a kind of “poetry” not beholden to truth or falsity.

As previously mentioned, logical positivists defined meaningfulness in terms of verification. “To be cognitively meaningful is to be either true or false; thus, a statement is meaningful if there is the right sort of method for testing truth or falsehood.” Analytic statements, on the other hand, are demonstrated true or false by mathematical or logical proof.

While operationalism and classical empiricism focus on the relation of a term to experience, the verificationism of logical positivists makes empirical meaningfulness a matter of a statement’s ability to meet experience, made possible partly due to advances in logic. As you can see, this is where philosophy really begins to take on a linguistic turn. Thus, a term can get its meaning from its role in making meaningful statements rather than being independently meaningful. Verification of a synthetic statement entails finding observations that speak to its truth. However, it is too stringent to require a sufficient number of observations to prove conclusively the verifiability of a synthetic statement. A weaker version of verification must suffice.

For logical positivists, theories need not get the world correct, but instead experience it right. Acupuncture is one example: One can respect reliable (at least within a certain domains) predictions that acupuncture theory makes and the cures that result, and avoid taking the theory’s assertions concerning energy channels and other pseudoscience seriously. Thus, for the logical positivists, the connections between theoretical terms are critical but for deriving observations, not for objectively describing reality. Often, statements that compose a scientific theory do not have to be true to be “good.” They do not attempt to describe the world but, instead, permit us to infer “this from that.”  “They can still play a needed role in a theory’s ability to take observational inputs and generate true observational outputs. This is the instrumental conception of scientific theories.”