Philosopher and American thinker, whose most important works are: Religion and Science (1874), Scientific Theism (1885), The way out of Agnosticism, or the Philosophy of Free Religion (1890) and The syllogistic Philophy or Prolegomena to Science (2 vol., 1906). Abbot promoted a "realism" or "scientific rationalism", anticipating Peirce with an epistemology based on the analysis of the objectivity of relations and a critique of nominalism. He argued that there are realities absolute, as space and, in general, the relational and necessary structure inherent in the universe, which he called "I ethics absolute or universal ethical person". Philosophical research is typical instrument the syllogism, that Abbot understood as a process of self-realization of the self. Such self-realization is achieved through knowledge in action, i.e., in morality, understood as an obedience that is free from ethical persons to an absolute moral law.