Abstract Theory is the debut solo album released by former Five member Abs.

The album failed to find success elsewhere, and resulted in Abs being dropped from his record label just months later.

The album received mixed to positive reviews from critics, comparing his material to that of his former band, Five.

[citation needed] Abs began work on the album following Five's split in late 2001.

In his retrospective review, Bren O'Callaghan of BBC said Abstract Theory "is capable of floating alone amidst a sea of chart craft".