Definitions

• Morality; concerned with the principles and rules of conduct, or the distinction between what is right and wrong behavior.
• Moral subject; a subject possessing a good of its own, and that can be wronged in a morally relevant sense. A moral subject deserves our consideration and concern when moral judgements are made, and is not necessarily able to understand and act on normative principles. Moral subjects may thus include humans, animals and non-conscious living beings.
• Moral agent; a being who is capable of understanding and acting on normative principles. By this definition humans are the only ones that can be termed moral agents.
• Moral Worth; to possess moral worth is to have a value in oneself and be worthy of moral consideration.
• Intrinsic Value; to have intrinsic value is to be valued as an end in itself, regardless of whether it is useful as a means to others. A mouse can for instance be of value for a cat, in the sense that it makes for an excellent meal, but in accordance with this term, it  also has a value in the sole regard of being a mouse.
• Instrumental Value; having instrumental value is to say that something is valued as a means to further some other end. A car is of value because it can get you from one place to another, but few would say that a car has any value in itself, independent of whether humans existed or not.
• Deontology; ethical theories arguing that for the most part,  an action is considered  right or wrong regardless of whether its consequences are good or bad.
• Holism; within environmental ethics holism holds that ecosystems and species have moral worth, and that individual interests and wellbeing should be subordinated to the good of the earth’s biotic community.

References

• Brennan, Andrew, Yeuk-Sze Lo 2008. . “Environmental Ethics” Available at Standford Encyclopedia of Philosophy
• Callicott, J. Baird 1986 “The Search for an Environmental Ethic.” In Tom Reagan, ed. Matters of Life and Death, 2d edition
• Goodpaster Kenneth E. 1978, «On Being Morally Considerable » New York: The Journal of Philosophy, Vol. 75, No. 6

Picture

• Study: Scott Akerman (CC BY 2.0)