Modern History Sourcebook: Spencer
- Excerpts from Spencer's 1857 article "Progress: Its Law and Causes." Includes some of Spencer's early thoughts on race and class.
- http://www.fordham.edu/halsall/mod/spencer-darwin.html

Laws In General
- A general consideration on the nature of laws, written by Spencer and published in 1864.
- http://www.marxists.org/reference/subject/philosophy/works/en/spencer2.htm

Reasons for Dissenting from the Philosophy of M. Comte
- Excerpts from Spencer's refutation of the positivism of Auguste Comte.
- http://www.marxists.org/reference/subject/philosophy/works/en/spencer.htm