F

• Formal theories (2 C, 3 P)
• Fringe theory (6 C, 8 P)

H

• Theories of history (22 C, 42 P)

L

• Law enforcement theory (2 C, 20 P)
• Linguistic theories and hypotheses (11 C, 36 P)

N

• Nursing theory (1 C, 16 P)

P

• Philosophical theories (14 C, 50 P)
• Proof theory (6 C, 95 P)

R

• Realism (2 C, 5 P)

S

• Scientific theories (22 C, 13 P)
• Social theories (18 C, 121 P)

T

• Theorems (7 C, 20 P)

• Theory

A

• Absolute theory
• Adaptive representation
• Arboreal theory
• Assembly theory

C

• Classification
• Cosmic pluralism
• Cultural theory of risk
• Culture theory

D

• Docking theory of olfaction
• 'Double Fish Hook' Strategy

E

• Ecosocial theory
• Explanation

F

• False tagging theory
• Fusion adaptive resonance theory

G

• Global Strategic Trends Programme

I

• Incrementalism
• Integrated threat theory
• Intergovernmentalism

J

• Jewish Indian theory

K

• Kluckhohn and Strodtbeck's values orientation theory

M

• Materiality (social sciences and humanities)
• Media system dependency theory
• Metallum Martis
• Millennial Day Theory
• Motivating language theory

N

• The Nature of the Judicial Process
• Nemesis (hypothetical star)

O

• Obstruction theory
• Odotope theory

P

• Peace ecology
• Philosophical theory
• Polysystem theory
• Principle of relativity
• Product ecosystem theory

R

• Relativistic dynamics
• Risk and actuarial criminology

S

• Scalar expectancy
• Situational theory of problem solving
• Skopos theory
• Space charge
• Spiral of silence
• Stoned ape theory
• Structuralist theory of mythology
• Supranational union

T

• Temporal theory (hearing)
• Theories of famines
• Theory of solar cells
• Toothpaste tube theory
• Translation theory

U

• Unknown God

V

• Vibration theory of olfaction