H’ Ben-Zion Uziel §
In every generation, conditions of life, changes in values, and technical and scientific discoveries create new questions and problems that require practical solutions. We are not permitted to avert our eyes from these issues and say Torah prohibits anything new, i.e., anything not expressly mentioned by earlier sages is automatically forbidden. We may not simply declare such matters permissible, nor can we let them remain vague and unclear, with each person acting with regard to them as he wishes. Rather, it is our duty to search all the halakhic sources, and based on what they explicate, to derive responses that address current-day issues.
— Hakham Ben-Zion Meir Hai Uziel - Introduction to Mishpetei Uziel, vol. 1.
H’ Eliyahu Hazzan §
Since the Holy Torah was given to physical human beings, who are always subject to changes stemming from differences in history and time, in rulers and decrees, in nature and climate, in states and realms - therefore, all Torah’s words were given in marvelous, wise ambiguity; thus, they can receive any true interpretation at any time… Indeed the Torah of Truth, inscribed by God’s finger, engraved upon the Tablets - will not change nor be renewed, for ever and ever
— Eliyyahu Hazan
H’ Hayim David HaLevy §
This is possible only because permission was given to Israel’s sages in each generation to renew halakha as appropriate to the changes of the times and events. Only by virtue of this was the continuous existence of Torah in Israel possible, enabling Jews to follow … There is nothing so flexible as the flexibility of Torah … it is only by virtue of that flexibility that the people of Israel, through the many novel and useful rulings innovated by Israel’s sages over the generations, could follow the path of Torah and its commandments for thousands of years
— Hayyim David Halevi - On the Flexibility of Halakha, 1989
H’ Yehuda Ibn Bulat §
it seems [to me] that in matter[s] of prohibition[s] and enactment[s], that if they were worthy, the Aharonim can assemble and abrogate the words of the Rishonim. This does not mean - God Forbid - that they should deliberately set themselves to oppose [the early authorities]. However, this is(?) the effect of the times that as a result of [different] causes changes its designs and what was beneficial to the Rishonim is harmful to the Aharonim. There is a principle agreed to all that “no decree can be passed on the community if the majority of the community can not endure it”
— Yehuda Ibn Bulat - Kelal Qaser (Constantinople 532, fol 10a)