This short text summarizes the perspectives proposed in [LM14f], where we appreciate the unity of the organism by looking at it from different viewpoints: biological time, theoretical symmetries and singularities, critical transitions. We explicitly borrow from the conclusions in some key chapters and introduce them by a reflection, also proposed in the book, on " incompleteness " , which we consider a pervasive notion in our forms of knowledge construction. Then we will introduce an approach to biological dynamics based on the integration of randomness in the theoretical determination: randomness does not oppose biological stability but contributes to it by variability, adaptation, and diversity. We see evolutionary and ontogenetic trajectories as continual changes of coherence structures, thus as symmetry changes within an ever-changing global stability.