Linnaean taxonomy can mean either of two related concepts:The particular form of biological classification (taxonomy) established by Carl Linnaeus, as set forth in his Systema Naturae (1735) and subsequent works. In his taxonomy Linnaeus described three kingdoms, each divided into classes, and the classes divided into lower ranks in hierarchical order. A general term for ranked classification of organisms. That is, taxonomy in the traditional sense of the word: rank-based scientific classification—which especially is used as opposed to the method of cladistic systematics, which groups organisms into clades.