drawing on three distinct butrelated concepts of coherence used in physics; global coherence, cross coherence and auto-coherence. The most common definition of coherence is "the quality of being logicallyintegrated, consistent and intelligible," as in a coherent argument. A related meaning is "alogical, orderly and aesthetically consistent relationship of parts" (McCraty & Tomasino, 2006,p. 4). In the following discussion we delve deeper into the meaning of coherence.Coherence in ordinary language means correlation, a sticking together, or connectedness;also, a consistency in the system. So we refer to people's speech or thought as coherent, if theparts fit together well, and incoherent if they are uttering meaningless nonsense, or presentingideas that don't make sense as a whole (Ho, 1998). Thus, coherence in this context refers towholeness and a global order: This is coherence as a distinctive organization of parts, therelations among which generate an emergent whole that is greater than the sum of the individualparts. In the example of organizing words in a coherent sentence, the meaning and purposeconveyed by the arrangement of the words is greater than the individual meaning of each word.It is important to note that all systems, to produce any function or action, must have theproperty of global coherence. The efficiency and effectiveness of the function or action can varywidely, however, and therefore does not necessarily result in a coherent flow of behavior. Globalcoherence does not mean that everybody or all the parts are doing the same thing at the sametime. Think of a jazz band for example, where the individual players are each doing his or herown thing, yet keeping in tune and step with the whole band. Coherence in this sense maximizeslocal freedom and global cohesion and resonance with the musical theme (Ho, 1998).In a living system global order or coherence must be sustained and maintained over time. Forexample, biochemist and geneticist Mae-Wan Ho (1998) has suggested that a whole livingsystem is a domain of coherent, autonomous activity that is coordinated across a continuum fromthe molecular to macroscopic to social levels.In physics, the concept of coherence is also used to describe the interaction or couplingamong different oscillating systems in which synchronization is the key idea in this concept.Synchronization describes the degree to which two or more waves are either phase or frequency-locked together, or when communication occurs between systems or modes without obstruction.Returning to the music example, a chord is composed of notes of different frequencies yetresonate as a harmonious order of sound waves. In physiology, coherence is similarly used todescribe the degree of coupling and harmonious interaction between two or more of the body'soscillatory systems such as respiration and heart rhythms. There are modes where they areoperating at different frequencies, and modes when they become entrained and oscillate at thesame frequency. This is also true for brain states in which the brainwaves can be momentarily inphase at different locations across the brain. The term cross-coherence is used to specify thistype aspect of coherence.INTEGRAL REVIEWDecember 2009Vol. 5, No. 2Another example, from a physiological systems perspective, is that people's thoughts,emotions and attitudes can either be aligned and coherent or incoherent. When