Meaning: The quote "This sense of power is the highest and best of pleasures when the belief on which it is founded is a true belief, and has been fairly earned by investigation" by William Clifford, a British mathematician and philosopher, reflects the idea that the feeling of empowerment that comes from holding true beliefs, based on thorough investigation and evidence, is a source of great pleasure and satisfaction. This concept touches on the intersection of knowledge, belief, and the ethical responsibility of individuals to base their beliefs on reasonable evidence.

William Clifford was a prominent figure in the field of mathematics, but he also made significant contributions to the philosophy of science and ethics. In his famous essay "The Ethics of Belief," Clifford argued that it is not only intellectually irresponsible but also morally wrong to hold beliefs without sufficient evidence. He emphasized the importance of critical inquiry and evidence-based reasoning in forming beliefs, as well as the ethical implications of spreading beliefs that lack a foundation in evidence.

The quote suggests that the feeling of power derived from holding true beliefs is particularly meaningful when those beliefs are the result of rigorous investigation and have been earned through the diligent pursuit of knowledge. This aligns with Clifford's broader philosophical stance that individuals have a moral obligation to critically examine their beliefs and ensure that they are grounded in evidence and reason.

The notion of "power" in this context can be understood as the confidence and assurance that comes with knowing that one's beliefs are well-founded and justified. It is not a power over others, but rather an internal sense of strength and conviction that arises from engaging in principled inquiry and arriving at well-supported conclusions. This type of power is distinct from mere assertion or dogma, as it is rooted in a commitment to intellectual honesty and a respect for the principles of evidence and reason.

Clifford's emphasis on the importance of evidence and investigation in forming beliefs reflects a broader philosophical tradition known as evidentialism. Evidentialism posits that beliefs are only justified to the extent that they are supported by evidence, and it places a premium on the rational justification of one's beliefs. According to this view, the pleasure and sense of power that come from holding true beliefs are intimately tied to the process of inquiry and the conscientious pursuit of knowledge.

Moreover, Clifford's assertion that the highest and best pleasures come from true beliefs suggests that the satisfaction derived from intellectual honesty and the pursuit of truth surpasses other sources of pleasure. This aligns with the classical philosophical notion that the life of the mind and the pursuit of knowledge are among the highest human goods, and that the fulfillment derived from intellectual integrity and genuine understanding is unparalleled.

In summary, William Clifford's quote encapsulates the idea that the sense of power derived from holding true beliefs is most fulfilling when those beliefs are grounded in evidence and have been arrived at through earnest investigation. This perspective underscores the ethical and epistemic importance of critically evaluating one's beliefs and emphasizes the profound satisfaction that comes from aligning one's convictions with the demands of reason and evidence.