The most direct links between philosophy of mathematics and computational complexity theory have thus far arisen in the context of discussions of the view traditionally known as strict finitism. This view is most prominently associated with Yessenin-Volpin (1961; 1970), who is in turn best known for questioning whether expressions such as \(10^{12}\) or \(2^{50}\) denote natural numbers. Presuming that such expressions denote at all, Yessenin-Volpin contended that they cannot be taken to describe what he referred to as feasible numbers – i.e. numbers up to which we may count in practice. On this basis, he outlined a foundational program wherein feasibility is treated as a basic notion and traditional arguments in favor of the validity of mathematical induction and the uniqueness of the natural number series are called into question. Antecedents for such a view may be found in (e.g.) Bernays (1935), van Dantzig (1955), and Wang (1958).[48]