To overcome mechanism and vitalism in biology Bertalanffy proposed a new standpoint, a view "...considered as a method of investigation, (which) we shall call 'organismic biology', and as an attempt as explanation, 'the system theory of the organism.' Every organism represents a system, by which term we mean a complex of elements in mutual interaction. (It means) that organisms are organized things and as biologists, we have to find out about it."

Describing life's vital factor in terms of systems relationships, which can be scientifically studied, impelled LvB to define the discovery of the laws of biological systems as the fundamental task of biology. Each law would be another contribution toward the whole explanation of causes and conditions that make the parts and processes of an organism to organize themselves for the survival of the whole. Such a discovery is evidently a continuous concern of those biologists interested in dealing scientifically with the riddle of life.

The problem of life is that of organization, where the parts and the whole exist in a state of total reciprocity, therefore the scientific study of any organism demands an analytical investigation of their isolated parts but closely related to an investigation of the whole system in operation. Living beings are organisms that organize themselves because they search to exist or 'need' to face successfully the effects of actions happening outside them, in the respective environment of every one. Then it is indispensable to consider them as open systems, i.e. matter flowing through, and that maintain themselves alive, by means of self organizing forces, in temporary quasi-equilibrium existence. It means that the dynamic existence of any system of such a kind is assured by means of a continuous exchange of matter and energy with its environment.

"Of all the wonders which life presents to us in such plenty, that of development is surely the greatest. Let us recall what it means: on the one hand we have this little drop of jelly which, as a fertilized ovum, represents the germ of an organism; on the other is the wonderful edifice of the complete living creature, with its myriad of cells, its endlessly complicated organs, characters and instincts. When we compare the beginning with the end of the process, it is easy to understand why it is that in all attempts to solve the great riddle of life, scientifically or philosophically, development is the starting point." The mystery of embryonic and the ability of living things to seemingly violate the law of entropy cannot even be examined by means of mechanical options. "In open systems we have not only production of entropy due to irreversible processes, but also import of negative entropy. This is the case in the living organism which imports [consumes nutrients with] complex molecules that are high in free energy. Thus living systems maintaining themselves in a steady state, can avoid the increase of entropy, and may even develop towards states of increased order and organization." From embryo onward and upward through evolution, biological entities flout the law of entropy by exhibiting negative entropy (negentropy) the tendency toward increasing order and complexity, the movement from formlessness to form.

"...steady state means that open systems are not just in flux, they are flux." The self-regulating balance of decay and synthesis of building and energy-yielding substances, which maintains the steady state of any organism, is the fundamental mystery of life; characteristics such as metabolism, growth, development, reproduction, autonomous activity are consequences of this basic fact.

Inside organismic biology the phenomenon of equifinality, which could not at all be explained by means of mechanistic assumptions, became scientifically evident as the ability of organisms to reach a given final goal from different initial conditions and in different ways. It is the organism's inner-directed ability to protect or restore its wholeness, as in the human body's mobilization of antibodies and its ability to repair injured skin and bone. The most dramatic form of equifinality is regeneration: lizards regrow lost tails, salamanders regrow lost limbs, and common garden worms regrow lost heads. Equifinality confirms that organisms pursue inner-directed goals, which they exhibit as a purposeful behavior that aims at maintaining their condition or achieving their intended condition. The explanation of this biological 'incident' makes reference to some ultimate end for which a thing or event is believed to be produced; it is the domain of teleology, which in the view of LvB "...represents an essential feature of reality, then science must take account of it" though some living matter does not exhibit this inner-directed behavior.