4. Conditions relating to solemnization of special marriages. - Notwithstanding anything contained in any other law for the time being in force relating to the solemnization of marriages, a marriage between any two persons may be solemnized under this Act, if at the time of the marriage the following conditions are fulfilled, namely:- (a) neither party has a spouse living; (b) neither party is an idiot or a lunatic; (c) the male has completed the age of twenty-one years and the female the age of eighteen years; (d) the parties are not within the degrees of prohibited relationship; and (e) where the marriage is solemnized outside the territories to which this Act extends, both parties are citizens of India domiciled in the said territories.