Article 21. Necessity renders prohibited things permissible.

Article 22. Necessity is estimated by the extent thereof.

Article 23. A thing which is permissible by reason of the existence of some excuse therefore, ceases to be permissible with the disappearance of that excuse.

Article 24. When a prohibition is removed, the thing to which such prohibition attaches reverts to its former status of legality.

Article 25. An injury cannot be removed by the commission of a similar injury.

Article 26. A private injury is tolerated in order to ward off a public injury. The prohibition from practice of an incompetent physician is derived from this principle.

Article 27. Severe injury is removed by lesser injury.

Article 28. In the presence of two evils, the greater is avoided by the commission of the lesser.

Article 29. The lesser of two evils is preferred.
Article 30. Repelling an evil is preferable to securing a benefit.

Article 31. Injury is removed as far as possible.

Article 32. Any want, whether of a public or private nature, is so dealt with as to meet the exigencies of the case. The validity of sale subject to a right of redemption is of this nature. The inhabitants of Bokhara having fallen badly into debt, this procedure was put into operation in order to meet the exigencies of the case.

Article 33. Necessity does not invalidate the right of another. Consequently, if a hungry person eats bread belonging to another, such person must later pay the value thereof.

Article 34. A thing which may not be taken may also not be given.

Article 35. It is forbidden to request the performance of a prohibited act.

Article 36. Custom is an arbitrator; that is to say, custom, whether public or private, may be invoked to justify the giving of judgment.

Article 37. Public usage is conclusive evidence and action must be taken in accordance therewith.

Article 38. A thing which it is customary to regard as impossible is considered to be impossible in fact.

Article 39. It is an accepted tact that the terms of law vary with the change in the times.

Article 40. In the presence of custom no regard is paid to the literal meaning of a thing.