在任何科学事业中取得成功都需要非凡的能力、勤奋和精力。
People of the same trade seldom meet together, even for merriment and diversion, but the conversation ends in a conspiracy against the public, or in some contrivance to raise prices.
逻辑学研究不仅仅是关于推理规则,而是关于推理本身的本质。