Xavier I think there are kind people here who will help you. I for one am willing to do so, but I would suggest you also do some work to help yourself. Here are some basic tips to help you start your research. 1. 万物一体论 was put forward by 程顥 (Song Dynasty) and 王阳明 (Ming Dynasty) as part of the Confucian school of philosophy. It asserted that "Every human and non-human belong to the one holistic whole". It was a way of looking at the world, and it advocated a certain way of life. 2. 仁 is kindness. 3. 恻隐之心 is compassion, empathy and sympathy. Now perhaps you would like to do some further work on your own and then let us see the fruits of your research. The contemporary socio-political background is that, as you know, the People's Republic of China is reviving Confucianism as a key element in moral education. This will necessarily lead you to study the key social trends and political events since the establishment of the Republic in 1949.

And just because universal kindness is not achieved, one loses his compassion.

I did a search for the source of this topic. Here is the reference. 讀經與中國文化的複興——蔣慶先生談兒童讀經面臨的問題 http://www.datongxuetang.com/2015/xueshu_1112/455.html The whole paragraph is， 申韩法术之学惨刻寡恩，源于老子将“道”绝对客观化、外在化，不能与人的主观仁心相联系，因而不能使人达到万物一体之仁而丧失恻隐之心。 I am an engineer and not familiar with philosophy. But based on common understanding, the translation should be, "Therefore, it cannot make one to achieve the thinking of fairness and empathy，lossing their kindness."

it's hard to explain, even though native speaker. it was about philosophy. Personally I think here "万物一体之仁" means a kind thought to the every thing in the world, and what you “feeling” about them, you feel every thing are equal, even plant and people, then you will respect every thing. while you cant get this "feel", you feel nature to treat thing in different rules, of course I am higher class than "him". This is my personal opinion, not quite exactly so, and I can tell you is you are learning the very deep Chinese Culture.

Xavier, how are you getting on with this piece of work? Let's look at your translation.