Jamieson, Fausset and Brown on James 3:7

7. every kind--rather, "every nature" (that is, natural disposition and characteristic power).

of beasts--that is, quadrupeds of every disposition; as distinguished from the three other classes of creation, "birds, creeping things (the Greek includes not merely 'serpents,' as English Version), and things in the sea."

is tamed, and hath been--is continually being tamed, and hath been so long ago.

of mankind--rather, "by the nature of man": man's characteristic power taming that of the inferior animals. The dative in the Greek may imply, "Hath suffered itself to be brought into tame subjection TO the nature of men." So it shall be in the millennial world; even now man, by gentle firmness, may tame the inferior animal, and even elevate its nature.