The foundational sugya records a dispute among the sages at Lod: Rabbi Tarfon held that action is greater, while Rabbi Akiva held that study is greater, and the collective ruling sided with study — not as an end in itself but because study leads to action, so that study takes precedence in time just as it takes precedence in judgment (Kiddushin 40b:8); the same episode appears in Sifrei Devarim 41:11-12, where Rabbi Yose HaGelili adds that the obligation to study Torah historically preceded the actual practice of several agricultural mitzvot by decades, reinforcing that study's priority is temporal and causal rather than a claim that study is the ultimate goal.
The Rambam codifies this conclusion as halacha: no mitzvah is equal in weight to Torah study because study leads to action, and therefore study takes precedence over action in every case (Mishneh Torah, Torah Study 3:3); he derives this same principle from the pasuk commanding Israel to learn the laws in order to observe them (Mishneh Torah, Torah Study 1:3), and he further rules that when a mitzvah can be performed by others, one should not interrupt Torah study to do it, but if not, one performs the mitzvah and returns to study (Mishneh Torah, Torah Study 3:4).
Pirkei Avot pushes toward the other pole, teaching that study is not the essential thing but action is (Pirkei Avot 1:17), and the Tanya explicitly invokes this teaching to explain that one interrupts Torah study to perform an active mitzvah that others cannot do, since deed is the purpose of man's descent into this world (Tanya, Part I; Likkutei Amarim 37:26-27).
Several Acharonim resolve the apparent tension by distinguishing stages: the Shenei Luchot HaBerit explains that one who does not yet know the halachot should prioritize study since it brings him to know what to do, but one who already knows the practical laws should prioritize pursuing the mitzvah itself, since the deed is the true purpose (Shenei Luchot HaBerit, Aseret HaDibrot, Shevuot, Ner Mitzva:102); similarly, the Menorat HaMaor states that since study brings a person to action, one must first learn in order to be able to properly fulfill positive commandments, beginning with practical laws before more abstract study (Menorat HaMaor).
Nefesh HaChaim and Rav Yerucham Levovitz both sharpen why study is called greater despite action being the goal: Nefesh HaChaim states that no action can be done properly without prior study, so study is itself considered action and also brings about all the mitzvot (Nefesh HaChaim), while Rav Yerucham Levovitz explains that the statement 'study leads to action' does not merely mean study teaches the proper way to act, but that no action whatsoever, however minor, can be performed correctly without full Torah study (Daas Torah (Rav Yerucham Levovitz)).
The Maharal frames the dispute conceptually: the view that action is greater holds that action is the true end since man is not a purely intellectual being, whereas Rabbi Akiva's view that study is greater rests on the principle that whatever precedes and causes another thing is greater than its effect, and study is the cause that brings about action (Maharal (Chiddushei Aggadot, Kiddushin 31)); this same causal logic is read into the sugya by Chiddushei Aggadot, Kiddushin 40, which explains that learning's greatness lies specifically in its being the cause of action, and that a cause is always greater than its effect.
A related page reading reinforces this independent-value reading: Shaarei Halacha uMinhag 5:121 explains that the phrase 'learning comes before action' refers to precedence in time, while Torah study also carries intrinsic importance beyond merely leading to action.
Supporting pesukim are brought throughout as the scriptural anchors for this hierarchy: Israel's declaration 'we will do and we will hear' (Shemot 24:7) and its echo in Mekhilta DeRabbi Yishmael, Tractate Bachodesh 5:10), Yehoshua's charge to meditate on the Torah day and night in order to observe all that is written in it (Yehoshua 1:8), and Moshe's charge to Israel to study the laws in order to keep them (Devarim 5:1), together establishing study as the pathway that issues in observance.