There is still no answer to many scientific questions and there exists an uncertain degree of knowledge with regard to major disciplines. The physical and behavioural sciences such as psychology and economics, which are so frequently looked to for certitude, do not always come up with clear cut answers; and unsubstantiated theories often disguise a lack of knowledge.

While one category of ignorance applies to what is not known, another category applies to the inability to assemble all the facts needed. For example, although there may be considerable understanding of the effects of single policies on single objectives, where multiple and sometimes conflicting effects and objectives of programmes and policies exist the processes for evaluating all these may be too complex, so that decisions are made in ignorance of all the relevant data.

Another type of ignorance allows for the knowledge to exist and also the capability and means to acquire it, but the will to do so is not present. Unwillingness to look at the facts constitutes intellectual bias. An emotional bias has the same effect, such as identification with a particular set of interests whether they are national, political, economic, ideological or religious. In the latter case, a tenet of Roman Catholic theology, for example, describes those who will never embrace Christianity due to their heredity, upbringing or environment, as 'invincibly ignorant', which aptly describes the 'closed' mind in any situation.

Computers facilitate the theft of money and property and the destruction of data when there are inadequate controls against their misuse. Crimes perpetrated by unauthorized access to keyboards, terminals and communications devices generally can be described as thefts, misapplications of assets, or destruction of information. These terms may apply to the misappropriation of money and real property, or of proprietary information and intangible assets. The misuse of the computer may involve the forgery of computer signatures such as authorizing codes; the creation of false accounts payable to disburse cheques; improper use of personal information; the creation of "virus" or "rogue" programmes which interfere in software operations and destroy data. All of these crimes include programming the erasure of any evidence of the computer crime perpetrated. Probably the fastest growing category of computer related crime is that involving electronic fund transfer systems. The most significant types of computer crime were: arson, sabotage and malicious damage of computer installations; system penetration, or "hacking"; unauthorized use of computer time; thefts of assets, including software; embezzlement of funds; defrauding of consumers and investors; and destruction or alteration of data (including college transcripts and diplomas) and software. The motive is usually personal financial gain, anger or revenge but another significant impetus is 'the intellectual challenge' associated with computer crime.

The absence of, or inadequate provision for, documentation and access controls for computer installations, facilitates computer crime. Unauthorized access to software and hardware is almost exclusively the means of crime perpetration. With authorized access, but with criminal collusion, two or more persons may commit crimes unnoticed, until financial audits, inventories, and computer operation system checks uncover the fraud or misuse. In the case of theft of intangible properties such as computer-stored patents of engineering, chemical or other designs, processes, or marketing and strategic data, the crime is exposed, if at all, by inferences drawn from the activities, products or knowledge shown by competitors.

Recreation and tourism are becoming popular to the extent that in many countries they have developed into a national industry; they are often accompanied by extensive damage to the environment. Aquatic ecosystems are particularly vulnerable to the effects of an increased tourist trade and the resultant building of hotel accommodations, sewage disposal works, roads, car parks and landing jetties on banks and coastlines; and the increased angling, swimming, water skiing, shooting or use of motor-boats in the water body. These all produce direct deleterious effects when conducted on a massive scale, including shore damage, chemical changes in the water, and sediments and biological changes in the plant and animal communities. Indirect effects are caused when small towns and villages near a water body are visited periodically by a large number of people; or by changes in the land usage within the drainage area often due to an increase in industrial sewage or agricultural run-off that is associated with the local growth of tourism.

Environmental disadvantages accompanying the over-exploitation of tourism include: despoiling of coastlines by construction of tourist facilities; pollution of the sea; loss of historic buildings to make way for tourist facilities; loss of agricultural land for airport development. Ownership of land and the control of components of the tourist industry are increasingly in the hands of non-residents and of companies based elsewhere, giving rise to serious problems of control. Often outside interests acquire the best sites and beaches and then exploit them in such a way that an overall tourist plan cannot be implemented at a later date.

Tourism places direct and indirect pressures on, and threats to, the conservation of species and habitats, and may cause disturbances to wildlife and increase pollution caused by transportation.

Disposal of waste produced by the tourism industry may cause major environmental problems. Such waste can generally be divided into: sewage and waste-water; chemical wastes, toxic substances and pollutants; and solid waste (garbage or rubbish). The effect of direct discharge of untreated sewage can lead to eutrophication, oxygen deficit and algal blooms.

A feeling of alarm caused by the expectation of danger, pain, disaster or other calamities, fear may lead to aggression and violence including war and conflict of all kinds. It may also lead to discrimination, conformism, inertia, alienation, delusion, dependency, lack of participation, corruption, injustice and inequality. Fear may exist in the form of general anxiety which has no object. Fear may also be phobic, that is, very specific to a particular object, condition, environment, etc, such as claustrophobia. Fear of grievous physical injury or death in the face of a real threat may cause tremor, sweating, heart palpitation, and involuntary passing of urine or faeces. Fear itself can be a cause of death, by shock or heart attack. Fear can grip whole armies or civilian populations.

Paraphilia was previously known as sexual perversion and sexual deviation. It is the experience of intense sexual arousal to atypical objects, situations, fantasies, behaviors, or individuals.

"The DSM-IV-TR describes paraphilias as "recurrent, intense sexually arousing fantasies, sexual urges or behaviors generally involving nonhuman objects, the suffering or humiliation of oneself or one's partner, or children or other nonconsenting persons that occur over a period of six months" (criterion A), which "cause clinically significant distress or impairment in social, occupational, or other important areas of functioning" (criterion B). (https://en.wikipedia.org/wiki/Paraphilia)