Idioms of thought in English

collect yourself/your thoughts

food for thought

an idea that makes you think seriously and carefully

The programme certainly provides plenty of food for thought.

give (somebody) pause for thought (also give (somebody) pause)

(formal) to make somebody think seriously about something or hesitate before doing something

Popular resistance to the measures should give the government pause for thought.

have second thoughts

to change your opinion after thinking about something again

You’re not having second thoughts about it, are you?

on second thoughts (British English) (North American English on second thought)

used to say that you have changed your opinion

I'll wait here. No, on second thoughts, I'll come with you.

a penny for your thoughts | a penny for them

(saying) used to ask somebody what they are thinking about

perish the thought

(informal or humorous) used to say that you find a suggestion unacceptable or that you hope that something will never happen

Me get married? Perish the thought!

school(s) of thought

a way of thinking that a number of people share

There are two schools of thought about how this illness should be treated.

He belongs to the school of thought that says that competition can be very stimulating for children.

a train of thought

the connected series of thoughts that are in your head at a particular time

The phone ringing interrupted my train of thought.

I lose my train of thought when there are distractions.

the wish is father to the thought

(saying) we believe a thing because we want it to be true

without a second thought

immediately; without stopping to think about something further

He dived in after her without a second thought.

I accepted the offer without a second thought.