All products of technology and science were limited in their development by certain natural principles.

You are very concerned about certain principles in this matter.

Each case is different, but there are certain broad principles we keep in mind.

You are merely required to put certain principles into practice at work.

We have already adopted certain principles here a few times this year.

Despite this, certain basic principles must have been common to all types of building.

There are certain principles that even every democratic government also has to maintain.

Certain other general principles can be extracted from the cases.

There are certain principles in the Bible, that you never give up.

Do not fear that I mean to thrust certain principles upon your attention.