Principle of criticism
On Ruslim.Org we adopt a principle for criticism:
Criticize only that which you know/love
By "know" we mean one is an expert in the field he/she is going to criticize. Furthermore, one is supposed to be in "love" with the field of criticism.
We do not expect a math teacher to (seriously) comment on biology. We do not accept criticism from an artist fairly accustomed to math practices.
Note, however, this rule has some exceptions. Noteworthy, a theologian taught philosophers what philosophy is without being a philosopher (in the meantime being accused of practicing philosophy amongst brother theologians). This theologian has all the rights to criticize philosophy.
Also, some "fields" do not need experts: one does not need biology to know what life is, although the former calls its objects "living things". One does not need Bernoulli theorem to claim that 2+2 is not 5.
So, this rule must not be taken to extremes.
Example 1: do you expect your child to learn math from BBC news? Yet, some people take their knowledge of religion, politics, and other sociologically relevant fields from that kind of sources…
Example 2: some renowned math professor decides to make his contribution to history. He writes a book where everything so nicely and logically connected to each other, each claim smoothly relates to the previously made propositions, but … he hastily mentions, all to support his derivations, that the kingdom of Alexander the Great has fallen under the raids of Mongols…
Example 3: A Nobel prize laureate in physics writes a book on meaning of life, where he defines life as water (indeed, all life is based on water). All science is easily derived afterwards. Similarly, a Nobel prize laureate in medicine gives a lecture on life, but his definition of life is somewhat different from what everybody understands as such. And he continues talking about cells…