Explainable artificial intelligence increasingly seeks to provide more than visualisations of feature importance or simplified descriptions of model outputs. For intelligent systems used in consequential settings, machine reasoning should be open to questioning, inspection, contextualisation, correction, and evaluation under uncertainty. This integrative review examines emerging approaches that may support this broader objective. It connects causal explainability and counterfactual reasoning with neuro-symbolic intelligence, knowledge-grounded inference, uncertainty-aware explanation, reliability evaluation, and human-centred interpretability. The review uses a structured integrative approach to compare how these paradigms represent causes, alternatives, rules, concepts, knowledge sources, inferential steps, confidence, and limitations. Causal and counterfactual approaches can support questions about mechanisms, contrasts, interventions, actionability, and recourse, but their conclusions depend on explicit assumptions, feasible alternatives, and appropriate causal evidence. Neuro-symbolic and knowledge-grounded approaches can make concepts, relations, rules, provenance, and intermediate reasoning more traceable, although symbolic structure or retrieved knowledge does not automatically ensure faithful, valid, or truthful explanation. Uncertainty-aware approaches can qualify predictions and explanations through uncertainty characterisation, calibration, confidence communication, robustness assessment, and human interpretation, but uncertainty estimates alone do not establish reliability. The synthesis indicates that no individual paradigm is sufficient. More defensible machine reasoning requires complementary evaluation of explanation fidelity, causal plausibility, knowledge validity, reasoning traceability, uncertainty communication, cognitive accessibility, contestability, and lifecycle accountability. Important research opportunities concern causal validation, feasible recourse, provenance governance, explanation uncertainty, hybrid-system evaluation, human-centred testing, and cross-paradigm assessment. The review contributes an integrated account of how machine reasoning may become not merely visible, but meaningfully open to question.