Why do these verbs take bare infinitives?

[a] It makes the tree grow. [b] I never heard him speak.

I’m wondering why causative and sense verbs (make, hear) license bare infinitives for their complement, instead of taking to infinitives? What semantic difference is there between bare and to infinitives?

I glimpse a clue that this adjective complement is “more immediately or directly visible (CGEL,p.263)” in ‘she looked happy’ than in ‘she looked to be happy’; to infinitives have meaning of modality, change, and potentiality (CGEL, pp.174, 1242, 1243). And I guess those verbs would take bare infinitives to denote concurrence of matrices and complements' actions. But I’ve not found any accounts of this. Why do they license bare infinitives?

(I've read the difference between their taking infinitive and gerund, in ELL and CGEL (p.1236-7): the verbs have the "whole event" of the infinitives and "a segment of" the gerund.)

Answer

It was not always thus...see the following http://www.kingjamesbibleonline.org/Psalms-23-2/