
Paul Ernest's Page  http://www.ex.ac.uk/~PErnest/
Based at School of Education, University of Exeter,
United Kingdom, includes the text of back issues of the Philosophy of
Mathematics Education Journal, and other papers on the philosophy of
mathematics and related subjects. 

Inconsistent
Mathematics  http://plato.stanford.edu/entries/mathematicsinconsistent/
Inconsistent mathematics is the study of the
mathematical theories that result when classical mathematical axioms are
asserted within the framework of a (nonclassical) logic which can
tolerate the presence of a contradiction without turning every sentence
into a theorem. By Chris Mortensen, from the Stanford
Encyclopedia. 

Constructive
Mathematics  http://plato.stanford.edu/entries/mathematicsconstructive/
Constructive mathematics is distinguished from its
traditional counterpart, classical mathematics, by the strict
interpretation of the phrase `there exists' as `we can construct'. In
order to work constructively, we need to reinterpret not only the
existential quantifier but all the logical connectives and quantifiers as
instructions on how to construct a proof of the statement involving these
logical expressions. From the Stanford Encyclopedia. 

On Gödel's Philosophy of
Mathematics  http://www.friesian.com/goedel/ A
paper by Harold Ravitch, Los Angeles Valley College. 

Nineteenth Century
Geometry  http://plato.stanford.edu/entries/geometry19th/
Philosophicalhistorical survey of the development of
geometry in the 19th century. From the Stanford Encyclopedia, by Roberto
Toretti. 