Our panel of 91 professional philosophers has responded to

170
 questions about 
Freedom
88
 questions about 
Physics
51
 questions about 
War
96
 questions about 
Time
287
 questions about 
Language
1280
 questions about 
Ethics
2
 questions about 
Culture
54
 questions about 
Medicine
58
 questions about 
Abortion
32
 questions about 
Sport
284
 questions about 
Mind
110
 questions about 
Biology
69
 questions about 
Business
110
 questions about 
Animals
75
 questions about 
Perception
374
 questions about 
Logic
80
 questions about 
Death
117
 questions about 
Children
81
 questions about 
Identity
208
 questions about 
Science
4
 questions about 
Economics
105
 questions about 
Art
23
 questions about 
History
89
 questions about 
Law
34
 questions about 
Music
392
 questions about 
Religion
77
 questions about 
Emotion
36
 questions about 
Literature
5
 questions about 
Euthanasia
70
 questions about 
Truth
218
 questions about 
Education
43
 questions about 
Color
27
 questions about 
Gender
67
 questions about 
Feminism
68
 questions about 
Happiness
124
 questions about 
Profession
574
 questions about 
Philosophy
39
 questions about 
Race
134
 questions about 
Love
58
 questions about 
Punishment
244
 questions about 
Justice
24
 questions about 
Suicide
154
 questions about 
Sex
151
 questions about 
Existence
2
 questions about 
Action
282
 questions about 
Knowledge
75
 questions about 
Beauty
31
 questions about 
Space
221
 questions about 
Value

Question of the Day

Like you, I'm puzzled by the form of the conditional "Only if A, then B." It doesn't seem to be idiomatic English. One might say "Only if you go to the party will I go," but one wouldn't say "Only if you go to the party, then I will go." That would be unidiomatic. So I presume that the conditional form you're learning is "Only if A, B" rather than "Only if A, then B." I would interpret "Only if A, B" as stating that A is a necessary condition for B, and therefore implying that B is a sufficient condition for A.

If one wants to say that A is both necessary and sufficient for B, then one can say "If and only if A, B" -- although "A if and only if B" would be a smoother way of saying it. In any case, make sure that your logic teacher really did say "Only if A, then B" and, if so, ask if he/she meant to say "Only if A, B."