Rabbi Desler in “strive for truth” explains that commandments fulfilled out of duty for G-ds sake enable the reception of the reward in the world to come described by the Gemmorah as “the righteous sitting…and enjoying the splendor of the Divine Presence.” However someone who served G-d in a humanistic way, with an ulterior motive must receive their reward in a similar vein.
Similarly the Alter Rebbe in chapter 39 of Tanya explains how “…when one engages [in divine service] explicitly not lishmah (for its own sake) but for an ulterior motive of self-glorification, as, for example, in order to become a scholar, and the like, then this motive, which is derived from kelipat nogah (a source of intermingled holiness and evil), clothes itself in his Torah study, and the Torah [studied for this motive] is in a state of exile within the kelipah (evil)…” indicating an agreement with Kant that ones motive matters tremendously.
However the Alter Rebbe goes on to explain “…when he returns to G-d, his Torah returns with him [from kelipah to holiness]. Therefore our Rabbis, of blessed memory, said, "One should always engage [in Torah and mitzvot, even shelo lishmah (with an ulterior motive)], for out of shelo lishmah he will certainly arrive at [study and observance] lishmah (out of duty), since it is certain that he will ultimately repent, whether in this incarnation or another, because "No one banished from Him [by his sins] will remain banished," [but will ultimately repent.” The Jewish view seems to agree with Kant. A moral action needs to be performed out of duty with good intentions; however the inability to do so should not deter someone from following the laws, as when a person repents his Torah learning with an ulterior motive will be redeemed and he will arrive at an observance for its own sake. The principle is the same, but there are technical differences between Kant and Orthodox Judaism.
Kant believed that by virtue of our rationality human beings have certain duties. Orthodox Judaism states that by virtue of our creation and ability we have a duty to serve G-d Vis a Vis (Pirkei Avos 6:11): "All that the Holy One, blessed be He, created in His world, He created solely for His glory." Kant believed that these are categorical, applying regardless of the consequences. Jewish law is for Orthodox Jews also categorical, demanding adherence regardless of the consequences. For example, Orthodox Jews should keep the laws of Shabbat regardless of the consequences. These laws are intrinsically good. At this point it could be argued that these laws are not categorical as they are suspended for the sake of preserving life; thus apparently making Orthodox Judaism, contrary to Kant, motivated by consequences, i.e. avoiding death. However in response it should be noted that the concept of suspending the Shabbat laws for preservation of human life, is sewn into the very fabric of the law itself, black and white in the 2nd chapter of Shabbat in the Rambams Mishneh Torah. Thus the maxim is not broken; rather the maxim is “keep the Shabbat as long as it does not endanger human life.” The apparent compromise, is not a compromise but from the same source of the Shabbat laws and thus intrinsically good and part of the maxim.
Kant thought there was only one basic categorical Imperative “act only on maxims which you can at the same time want to be universal laws.” This is known as Kant’s principle of universalisability. This notion is a version of the main principle in Orthodox Judaism as said by Hillel to a potential convert who wanted to know all of Judaism whilst standing on one foot. “Don’t do to others what you wouldn’t want them to do to you. All else is commentary.” However it could be argued that Hillel’s principle is not necessarily a version of universalisability at all. Rashi (Shabbos 31a,) translates others as referring to G-d, whilst the Alter Rebbe in Tanya refers to the others explicitly as the Jewish people. The Rebbe Rashab of Lubavitch said on the contrary, equality is a sickness. There are some people who are more privileged than others and therefore have greater responsibility. There are other places in Orthodox Judaism that recognize human rights but Hillel’s dictum cannot be compared to universalisability. On the contrary, Jews have one set of laws, the 613 mitzvot whilst non-Jews have only 7 noachide laws, showing that Orthodox Judaism does not believe that morality can be universalized. Kant believed people were obligated to respect people as an end in themselves and never as a means, this includes ones self. One of the principles of Judaism is self-negation, viewing ones self as completely devoted to a higher cause, i.e. serving G-d. For Kant, somebody who negates his own identity could, (taken to its logical end) would be guilty of immorality. Thus we have a clear difference between Kant and Orthodox Judaism.
Relativism is a view that turns morality into merely a description of the values held by a particular society at a particular time. Moral judgments can only be judged true or false relative to particular society. Progressive Judaism is in their own eyes a combine an absolutist approach to ethics with a relative approach. This can be demonstrated clearly in the preamble to the statement of principles for Reform Judaism adopted at the 1999 Pittsburgh convention: “The great contribution of Reform Judaism is that it has enabled the Jewish people to introduce innovation, while preserving tradition.” This is how progressive Jews see themselves, on the one hand they are relative, they are innovative, they change attitudes depending on innovative views of society, and on the other hand these attitudes are changed to fit in with certain absolute principles for progressive Jews. This is a result of the progressive attitudes to the Torah. All progressive movements seem to agree that the Torah at least contains much that is spiritual and inspiring, yet also the word of fallible human beings. As a result it is down to them to extract that which is good, eternal and spiritual from the Torah, a work written by human beings and thus inevitably fallible. The fact that the Torah seems to contain certain principles of an absolute value, is expressed in documents like the statement of principles for Reform Judaism adopted at the 1999 Pittsburgh Convention Central Conference of American Rabbis, which affirms certain tenets in Judaism. The truth is this issue, the absoluteness of the Torah, directly impacts the relativity of progressive Judaism. This can be illustrated by the fact that the Reform movement who consider the Torah a result of a divine encounter, consider it to contain certain timeless teachings which make up tenets of Judaism. Liberal Judaism on the other hand does not directly acknowledge the torah as having anything to do with an encounter with the divine and as a result is probably the most relative branch of progressive Judaism, as shown by its liberal attitude to conversion reform.
Progressive Jews are generally not dogmatic and prepared to change, and thus highly relative. This can well be illustrated by charting the view of Progressive Judaism to the land of Israel since its inception. Originally Reform Judaism rejected the idea that Jews would re-create a Jewish state in their ancestral homeland. Reform Judaism rejected the classical rabbinic teaching that the Jews were in exile ("galut"). Reform Jews ceased to declare Jews to be in exile; for the modern Jew in America and England, had no cause to feel that the country in which he lives is for him a strange land. Many Reform Jews went so far as to agree that prayers for the resumption of a Jewish homeland were incompatible with desiring to be a citizen of a nation. Thus, the Reformers implied that for an American Jew to pray from the original siddur was tantamount to dual loyalty, if not outright treason. In the U.S., Reform intellectuals argued that their commitment to the principles of equal rights and the separation of religion and state precluded them from supporting Zionism. In a Jewish state, they contended, the Arabs would be second-class citizens and Judaism would be the official religion. Since and the establishment of the modern , Reform Judaism has largely repudiated ; the official platform of Reform Judaism is now .
Another aspect where reform Jews are prepared to change is ironically their view of Jewish law. The following statement was made at the 1885 Pittsburgh conference: 4. “We hold that all such Mosaic and rabbinical laws as regulate diet, priestly purity, and dress originated in ages and under the influence of ideas entirely foreign to our present mental and spiritual state. They fail to impress the modern Jew with a spirit of priestly holiness; their observance in our days is apt rather to obstruct than to further modern spiritual elevation.,” By 1999 this had evolved to: “We are committed to the ongoing study of the whole array of mitzvot and to the fulfilment of those that address us as individuals and as a community. Some of these mitzvot, sacred obligations, have long been observed by Reform Jews; others, both ancient and modern, demand renewed attention as the result of the unique context of our own times. So Progressive Judaism is extremely relative in that it is re-highlighting the importance of absolute laws.
In conclusion Orthodox Judaism heavily overlaps with Kantian ethics however there are some major technical differences in application. Progressive Judaism is largely relative however there is still a sense of absolute principles motivating direction.
A statement of principles for Reform Judaism adopted at the 1999 Pittsburgh Convention Central Conference of American Rabbis – May 1999
Maimonides- Guide for the Perplexed – Part.1. Chapter 2
Groundwork of the Metaphysic of Morals- Kant 1972
The wolf shall lie with the Lamb-The Messiah in Hasidic Thought – Shmuely Boteach 1993