Modes of nature—There are three guṇas, or modes of material nature: goodness (sattva-guṇa), passion (rajo-guṇa) and ignorance (tamo-guṇa). They make possible our mental, emotional and physical experiences of the universe. Without the influence of the modes, thought, value judgement and action are impossible for the conditioned soul. The English word mode, as used by Śrīla Prabhupāda in his translations of Vedic literature, best conveys the sense of the Sanskrit term guṇa (material quality). Mode comes from the Latin modus, and it has a special application in European philosophy. Modus means measure. It is used to distinguish between two aspects of material nature: that which is immeasurable (called natura naturans, the creative nature) and that which seems measurable (called natura naturata, the created nature). Creative nature is a single divine substance that manifests, through modes, the created nature, the material world of physical and mental variety. Being immeasurable (in other words, without modes), creative nature cannot be humanly perceived. Created nature (with modes) seems measurable, hence we do perceive it. Modus also means a manner of activity. When creative nature acts, it assumes characteristic modes of behavior: creation, maintainance and destruction. Bhagavad-gītā (14.3-5) presents a similar twofold description of material nature as mahat yoni, the source of birth, and as guṇa prakṛti, that which acts wonderfully through modes. Material nature as the source of birth is also termed mahad-brahman, the great or immeasurable Brahman. Mahad-brahman is nature as the divine creative substance, which is the material cause of everything. Material cause is a term common to both European philosophy (as causa materialis) and Vedānta philosophy (as upadāna kāraṇa). It means the source of ingredients that make up creation. We get an example of a material cause from the Sanskrit word yoni, which literally means womb. The mother's womb provides the ingredients for the formation of the embryo. Similarly, the immeasurable creative nature provides the ingredients for the formation of the material world in which we live, the seemingly measurable created nature. The clarity of this example forces a question: what about the father, who must impregnate the womb first before it can act as the material cause? This question is answered by Kṛṣṇa, the speaker of the Bhagavad-gītā, in verse 14.4: ahaṁ bīja-pradaḥ pitā, I am the seed-giving father. In Vedānta philosophy, this factor of causation is termed nimitta-mātram (the remote cause). It is important to note that by presenting creation as the result of the union of two causes (the material and the remote), the Bhagavad-gītā rejects the philosophy of Deus sive natura, the identity of God and nature. In short, though creative nature may be accepted as the direct cause of creation, it is not the self-sufficient cause of creation. The seed with which Kṛṣṇa impregnates the womb of creative nature is comprised of sarva-bhūtānām, all living entities (Bg. 14.3). And Bg. 14.5 explains that when Kṛṣṇa puts the souls into the womb of material nature, their consciousness is conditioned by three modes, or tri-guṇa. The modes are three measures of interaction between conscious spirit and unconscious matter. The modes may be compared to the three primary colors, yellow, red and blue, and consciousness may be compared to clear light. The conditioning (nibhadnanti: they do condition) of consciousness upon its entry into the womb of material nature is comparable to the coloration of light upon its passing through a prism. The color yellow symbolizes sattva-guṇa, the mode of goodness. This mode is pure, illuminating, and sinless. Goodness conditions the soul with the sense of happiness and knowledge. The color red symbolizes the rajo-guṇa, the mode of passion, full of longings and desires. By the influence of passion the soul engages in works of material accomplishment. The color blue symbolizes tamo-guṇa, the mode of ignorance, which binds the soul to madness, indolence and sleep. As the three primary colors combine to produce a vast spectrum of hues, so the three modes combine to produce the vast spectrum of states of conditioned consciousness that encompasses all living entities within the universe. See Kṛṣṇa, Threefold miseries.