Dewey Decimal System: 21st edition
000 | 100 | 200 | 300 | 400 | 500 | 600 | 700 | 800 | 900



100 Philosophy & psychology
101 Theory of philosophy
102 Miscellany of philosophy
103 Dictionaries of philosophy
104 Not assigned or no longer used
105 Serial publications of philosophy
106 Organizations of philosophy
107 Education, research in philosophy
108 Kinds of persons in philosophy
109 Historical treatment of philosophy

110 Metaphysics
111 Ontology
112 Not assigned or no longer used
113 Cosmology (Philosophy of nature)
114 Space
115 Time
116 Change
117 Structure
118 Force & Energy
119 Number & quantity

120 Epistemology, causation, humankind
121 Epistemology (Theory of knowledge)
122 Causation
123 Determinism & indeterminism
124 Teleology
125 Not assigned or no longer used
126 The self
127 The unconscious & the subconscious
128 Humankind
129 Origin & destiny of individual souls

130 Paranormal phenomena
131 Occult methods for achieving well-being
132 Not assigned or no longer used
133 Parapsychology & occultism
134 Not assigned or no longer used
135 Dreams & mysteries
136 Not assigned or no longer used
137 Divinatory graphology
138 Physiognomy
139 Phrenology

140 Specific philosophical schools
141 Idealism & related systems
142 Critical philosophy
143 Intuitionism & Bergsonism
144 Humanism & related systems
145 Sensationalism
146 Naturalism & related systems
147 Pantheism & related systems
148 Liberalism, eclecticism, traditionalism
149 Other philosophical systems

150 Psychology
151 Not assigned or no longer used
152 Perception, movement, emotions, drives
153 Mental processes & intelligence
154 Subconscious & altered states
155 Differential & developmental psychology
156 Comparative psychology
157 Not assigned or no longer used
158 Applied psychology
159 Not assigned or no longer used

160 Logic
161 Induction
162 Deduction
163 Not assigned or no longer used
164 Not assigned or no longer used
165 Fallacies & sources of error
166 Syllogisms
167 Hypotheses
168 Argument & persuasion
169 Analogy

170 Ethics (Moral philosophy)
171 Systems & doctrines
172 Political ethics
173 Ethics of family relationships
174 Economic & professional ethics
175 Ethics of recreation & leisure
176 Ethics of sex & reproduction
177 Ethics of social relations
178 Ethics of consumption
179 Other ethical norms

180 Ancient, medieval, Oriental philosophy
181 Oriental philosophy
182 Pre-Socratic Greek philosophies
183 Sophistic & Socratic philosophies
184 Platonic philosophy
185 Aristotelian philosophy
186 Skeptic and Neoplatonic philosophies
187 Epicurean philosophy
188 Stoic philosophy
189 Medieval Western philosophy

190 Modern Western philosophy
191 Modern Western philosophy United States & Canada
192 Modern Western philosophy British Isles
193 Modern Western philosophy Germany & Austria
194 Modern Western philosophy France
195 Modern Western philosophy Italy
196 Modern Western philosophy Spain & Portugal
197 Modern Western philosophy Soviet Union
198 Modern Western philosophy Scandinavia
199 Modern Western philosophy Other geographical areas