It attached him at first to Spinoza and later to mathematical logic.
The importance of mathematical logic seems to be mainly in the facilitation of logical expression through symbols.
The modern development of mathematical logic dates from Boole's Laws of Thought .
Mathematical logic, even in its most modern form, is not directly of philosophical importance except in its beginnings.
Take such a statement as, “The class of people interested in mathematical logic is not very numerous.”
Obviously this reduces itself to, “Not very many people are interested in mathematical logic.”
Then our statement is, “Not three people are interested in mathematical logic.”